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HEP Seminars

25 Apr 2018

UCL HEP Seminars 1994-2017

15/12/2017 : Silvia Pascoli (Durham)

Going beyond the standard 3-neutrino mixing scenario

Although the standard 3 neutrino mixing scenario fits very well most existing data, the possibility that new effects, e.g. sterile neutrinos, NSI…, exist is still open. In this talk I will focus mainly on sterile neutrinos. They are neutral fermions which do not have Standard Model interactions but mix with light neutrinos. They constitute a minimal extension of the standard model. They have interesting signatures in cosmology and in laboratory searches. I will review the current situation, discussing the hints for their existence and their tests in neutrino oscillation, beam dump, SBN, DUNE and other experiments. I will conclude presenting a possible explanation of the MiniBooNE excess which is compatible with current data.

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08/12/2017 : NOTE UNUSUAL TIME & PLACE: 3pm Massey: Mauricio Bustamante (Niels Bohr Institute)

Heaven-sent neutrino interactions from TeV to PeV

Neutrino interactions are vital to particle physics and astrophysics. Yet, so far, they had remained unprobed beyond neutrino energies of 350 GeV. Now, thanks to the discovery of high-energy astrophysical neutrinos by IceCube, we have measured neutrino-nucleon cross sections from a few TeV up to a few PeV. We did this by using the Earth itself as a target: neutrino interactions with matter inside the Earth imprint themselves on the distribution of neutrino arrival directions at the detector. When measuring high-energy particle interactions, the sky is the limit.

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01/12/2017 : Anthony Hartin (UCL)

Strong field QED effects in the quantum vacuum generated by laser-electron interactions

When considered in a non-perturbative QFT, the interactions of intense lasers and relativistic charged particles lead to novel strong field QED effects amenable to experimental tests with available technology. I review the theory and simulation strategy necessary in order to design discovery experiments for these effects. The intense laser field is taken into account exactly in the bound Dirac equation whose solutions are required for different field configurations. The simulation strategy requires a PIC code combined with a monte-carlo of the quantum interactions. The workhorse process for such experiments is the trident process which I will also review.

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24/11/2017 : Mitesh Patel (Imperial)

Anomalous measurements at the LHCb experiment

A number of measurements of B-meson decays made at the LHCb experiment give anomalies with respect to the predictions of the Standard Model. The status of the relevant measurements, the connections between them and their theoretical interpretation will be discussed, along with the prospects for the future.

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17/11/2017 : Pontus Stenetorp (UCL)

DIS CDT seminar: Artificial Intelligence for Reading the Scientific Literature

We are currently experiencing an unprecedented increase of interest in applying Artificial Intelligence methods for various tasks. Spurred on advances using modern reincarnations of neural networks – Deep Learning – machine learning-based approaches have seen recent successes in complex games like Go, autonomous vehicles, and language-based question answering. In this talk I will present the current state of the art in Natural Language Processing (NLP) and its limitations. I will then relate this to previous and ongoing efforts in applying NLP-methods to the scientific literature – allowing scientists to cope with an ever increasing number of publications. Primarily I will cover ongoing work from the UCL Machine Reading group on text-based multi-step inference applied to the biomedical literature and a collaboration with the UCL Space & Climate Physics to track astronomical measurements in the astrophysics literature.

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[Video]

10/11/2017 : John LoSecco (Notre Dame)

The History of the Atmospheric Neutrino Anomaly

This talk covers the early days of particle astrophysics when it was slowly realized that the major background to proton decay, atmospheric neutrino interactions, were an important discovery in their own right.

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03/11/2017 : Moritz Backes

Recent results from Supersymmetry Searches at ATLAS

This talk discusses a selection of the latest ATLAS results for searches for supersymmetric (SUSY) particles performed with pp collisions at a centre-of-mass energy of 13 TeV, using the full 2015 and 2016 dataset. Weak and strong production of SUSY particles in both R-Parity conserving and violating scenarios are considered assuming either prompt decays or longer-lived states.

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27/10/2017 : Jens Dopke (RAL)

Reading charcoal: Using HEP detectors to decipher papirii

I will introduce the problem of reading ancient documents, in this particular project working on reconstruction of text from scrolls found in Herculanuem near Mt. Vesuvis. These are made from papyrus and have been written on using organic inks. After the eruption of Mt. Vesuvius in 79 AD, these been slow-cooked under exclusion of oxygen, and hence turned into lumps of charcoal. All attempts of unrolling these subjects have been destructive. First indications show that dark-field x-ray imaging allows to make the ink of these documents visible and there is good hope that this assumption holds for multi-layered documents that cannot be unrolled. I will introduce dark-field x-ray imaging, report on where we are with the project, what’s lacking at the moment and where we plan to get to within the next year(s).

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20/10/2017 : Valerio Dao: NOTE: unusual time and location: 3pm Harrie Massey

Physics with Hbb at ATLAS

Since its discovery in 2012 the Higgs boson particle has opened new possibilities to further improve our understanding of the Standard Model physics landscape. Precise characterisation of its production and its properties could be used to indirectly probe for new physics effects and, at the same time, the decay of new particles could directly lead to signatures with a SM-like Higgs boson in the final state. The decay of the Higgs boson into a b-quark pair has, in this respect, a key role; while experimentally very challenging, the large branching ratio makes it the largest contributor to the total width of the Higgs boson and, thanks to the large rate, provides the best chance to see evidence for new phenomena that lead to deviations at high pT. Recently the ATLAS collaboration achieved an important milestone by obtaining the evidence for the H->bb decay in the associated production of the Higgs boson and a vector boson using Run2 data at 13 TeV. This seminar will mainly focus on this recent result discussing the experimental challenges that have been faced to extract the signal from a very large background. In addition, key examples of how H->bb signature could be used for directly searching for new physics effects will be given.

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01/09/2017 : Evan Niner (Fermilab)

Deep Learning Applications of the NOvA Experiment

The NOvA experiment is a long-baseline neutrino oscillation experiment that uses two detectors separated by 809 kilometers to measure muon neutrino disappearance and electron neutrino appearance in the beam produced at Fermilab. These oscillation channels are sensitive to unknown parameters in neutrino oscillations including the mass hierarchy, θ23, and CP violation. In this talk I will focus on the development and application of deep learning algorithms to the task of event reconstruction and classification in NOvA. These algorithms, adapted from computer vision applications, resulted in a performance gain equivalent to a 30% increase in exposure in the 2016 analysis. I will also look at future deep learning applications.

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12/07/2017 : Steven Prohira (Kansas University)

Radio interactions with particle-shower plasmas, with implications for high-energy astro-particle physics

The collision of a high-energy particle with stationary matter, such as ice, results in a shower of secondary particles. As these secondary particles traverse the interaction medium, cold ionization electrons are produced. For high enough primary particle energies, this cloud of ionization electrons is dense enough to form a tenuous plasma which may reflect radio-frequency (RF) energy. As such, RF scatter techniques have been proposed as a robust technology to remotely detect such high-energy particle interactions by illuminating a detection volume with RF energy and remotely monitoring the same volume for a reflected RF signal from a particle-shower plasma. Though the Telescope Array RADAR (TARA) experiment, the first dedicated attempt at the radio-scatter method, yielded no results, the intriguing lack of signal has caused renewed interest in the technique. Surprisingly, a dedicated laboratory measurement of RF scatter from particle-showers has never been performed at high (GeV) energies. This talk will discuss experimental results from TARA and will detail a laboratory measurement to take place at the End-Station facilities at SLAC to quantify the parameters of the particle-shower plasma. A high-energy electron beam will be fired into a large target to initiate a shower from which RF will be reflected. The observables from this measurement will be discussed, along with outlook.

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23/06/2017 Prof. Tsutomu Yanagida (IPMU, U. of Tokyo)

The Origin of Matter in the Universe

Paul Dirac proposed the baryon symmetric universe in 1933. This proposal has become very attractive now since it seems that all pre -existing asymmetry would have been diluted if we had an inflationary stage in the early universe. However, if our universe began baryon symmetric, the tiny imbalance in numbers of baryons and anti-baryons which leads to our existence, must have been generated by some physical processes in the early universe. In my talk I will show why the small neutrino mass is a key for solving this long standing problem in understanding the universe we observe today.

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16/06/2017 Sarah Bridle (Manchester)

Gastrophysics: Food security for astro/physicists

In this seminar I will describe my motivations for being interested in food research, and my belief that STFC researchers bring a lot of relevant skills to the challenges of providing food that consumers want. The STFC Food Network+ aims to bring STFC researchers and facilities together with food researchers and industry, through network meetings and funding for new projects. Some background about food: There is an impending perfect storm of pressure on our food production system, with increasing population and changing consumer tastes, in the face of rising temperatures and extreme weather events. Tim Gore, head of food policy and climate change for Oxfam, said “The main way that most people will experience climate change is through the impact on food: the food they eat, the price they pay for it, and the availability and choice that they have.”. Yet, at the same time, food production is a bigger contributor to climate change than transport. A 2014 Chatham House report states “Dietary change is essential if global warming is not to exceed 2C.”.

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02/06/2017 : Edward Daw (Sheffield)

Axions and Axion-Like Particles

In recent years, searches for new physics beyond the standard model have focussed on the electroweak scale, using channels that are reachable in high energy accelerators and through induced interactions of hypothesised electroweak-scale relic particles (WIMPs) in tonne-scale direct search experiments. A second possibility which is scientifically just as well-motivated is that the dark matter consists of much lighter pseudoscalars, called axions, whose origin is in low energy quantum chromodynamics, whose coupling to ordinary matter is feeble because their low mass, and consequently their feeble couplings to other particles, renders them 'invisible' to ordinary accelerator searches. The same feeble couplings mean that axions have very long decay times, so that relic axions generated in the very early Universe may be the dark matter evidenced through its gravitational effects today. I shall survey the field of axion-sector experimental searches. Experiments that look directly for the axion itself attempt to induce dark matter axions to convert into microwave photons in closed electromagnetic resonators. Other experiments identify other by-products of the symmetry breaking mechanism that may have yielded axions; these other by-products are sometimes called ALPs (axion-like particles), and experiments to search for ALPs typically use a 'light shining through a wall' technique. Overall this is an exciting and growing field. I will also discuss some of my own work on axion searches with the ADMX experiment, aimed towards improvements in the sensitivity and search rate of such experiments by means of novel modifications to the resonant detector design.

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26/05/2017 : Leigh Whitehead (CERN)

Sterile Neutrino searches with MINOS and MINOS+

Three-flavour neutrino oscillations have proved very successful in describing the observed neutrino oscillation data. However, there are also some anomalies, including the excesses of appeared electron neutrino interactions in LSND and MiniBooNE, and a sterile neutrino state at a larger mass-splitting scale can provide an explanation for these results. The MINOS/MINOS+ experiment was a long-baseline neutrino experiment in the US, collecting beam and atmospheric neutrino interactions from 2003 until 2016. MINOS was optimised for the study of muon neutrino disappearance in the NuMI beam at Fermilab. The continuation of the experiment with a medium energy beam configuration is called MINOS+. A sterile neutrino in MINOS/MINOS+ would appear as a modulation on the three-flavour oscillations. A search for sterile neutrinos has been performed using charged-current and neutral-current interactions in two detectors separated by a distance of 734km. The inclusion of two years of MINOS+ data and an improved fit method provides a much increased sensitivity over the previous MINOS result that was combined with Daya Bay.

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19/05/2017 : Gabriel Facini (UCL)

Searches for new phenomena with the ATLAS detector

Many theories beyond the Standard Model (BSM) predict new phenomena accessible by the LHC which prevent the need of fine-tuning of the Higgs Boson mass or expand the gauge sectors of the SM or the nature of Dark Matter for example. Searches for new physics models are performed using the ATLAS experiment at the LHC focusing on exotic signatures that can be realized in serval BSM theories. The results reported use the pp collision data sample collected in 2015 and 2016 by the ATLAS detector at the LHC with a centre-of-mass energy of 13 TeV.

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05/05/2017 : Christopher McCabe (GRAPPA)

Low energy signals in xenon detectors: from supernova neutrinos to light dark matter

One of the major achievements of the LUX collaboration was to accurately calibrate xenon dark matter direct detection experiments to sub-keV energies. This means that reliable predictions of low-energy signals can now be performed. In this talk, I’ll explore new low-energy signals from neutrinos and low-mass dark matter that could be measured with the forthcoming generation of multi-tonne xenon detectors. Based primarily on arXiv:1606.09243 and arXiv:1702.04730.

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28/04/2017 : Tommi Tenkanen (QMUL)

Observational properties of feebly interacting dark matter

Can dark matter properties be constrained if dark matter particles interact only feebly with the Standard Model fields? The answer is yes. By studying both cosmological and astrophysical constraints, we show that stringent constraints on dark matter properties can be derived even in case the dark matter sector is practically uncoupled from the Standard Model sector. By taking the Higgs portal model as a representative example, we study in detail scenarios where the hidden sector does not thermalize with the Standard Model sector and, among other things, derive a lower bound on dark matter self-interaction strength.

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21/04/2017 : Jonas Lindert (IPPP Durham)

High-precision predictions for V+jet production

In LHC searches for Dark Matter one of the dominant systematic uncertainties arises from the determination of the irreducible Z(->vv)+jet background. The modelling of this background relies on accurate measurements of V+jet production processes with visible final states and their extrapolation to the signal region via a global fit based on high-precision Standard Model predictions for pp->W+jets, pp->Z+jets and pp->gamma+jets including higher-order QCD and EW corrections. I will present such predictions with a focus on the mandatory determination of robust estimates of remaining theoretical uncertanties at the percent level and their correlation amongst processes.

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07/04/2017 Luise Skinnari(Cornell)

Track-triggering at CMS for the High-Luminosity LHC

The high luminosity upgrade of the LHC, scheduled for 2024-2025, will increase the luminosity by a factor of 10 beyond the original LHC design. The resulting large datasets will allow precise measurements of Higgs properties, searches for rare processes, and much more. To cope with the challenging environment from the high luminosity, significant upgrades will be required for the LHC experiments. A key upgrade of the CMS detector is to incorporate tracking information in the hardware-based trigger. We are exploring different strategies for performing the hardware-based track finding, including a fully FPGA-based approach. I will give an overview of the CMS track trigger upgrade, describe its expected performance, and show results from developments of a hardware demonstrator system.

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31/03/2017 Andreas Warburton (McGill/[UCL])

Searches for New Physics on the Intensity Frontier: The Belle II Experiment

The Belle II collaboration comprises over 600 physicists from 23 countries building a detector on the high-luminosity SuperKEKB electron-positron collider in Japan. The detector, a successor to the successful BaBar and Belle experiments, has capabilities complementary to efforts with similar goals at the LHC and is the latest experimental tool in the now three-decade-long B-factory era. I will outline the prospects for discoveries of new physics at Belle II and discuss the latest status and schedule of the accelerator and detector upgrades, currently in progress.

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24/03/2017 : Jose No (KCL)

Beyond simplified models for dark matter searches @LHC: Making a case for the pseudoscalar portal

The Higgs sector is a well-motivated portal to dark matter (DM). I discuss scalar/pseudoscalar portal models for DM, as a powerful tool to exploit the complementarity between LHC searches and direct/indirect DM detection experiments, and their connection to Higgs physics. I then analyze the shortcomings of so-called "simplified DM models" in this context, highlighting the key physics these models fail to capture and its impact on LHC searches.

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10/03/2017 Mark Lancaster (UCL)

The Fermilab Mu2e Experiment

In the SM the only mechanism to violate charged lepton flavour conservation is via neutrino oscillations which results in a branching rate for neutrinoless muon interactions of order 10^-50. As such any observation of a neutrinoless muon interaction would be evidence of new physics. In this talk I will describe the Fermilab Mu2e experiment that is seeking to detect the neutrinoless conversion of a muon to an electron in the field of a nucleus using 10^20 muons with a branching ratio sensitivity down to 6x10^-17 : a factor of 10^4 better than the previous limit which allows the experiment to probe new physics mass scales up to 8000 TeV, well beyond that probed by direct searches at the LHC.

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03/03/2017 Fady Bishara (Oxford)

The next frontier for Higgs couplings

The LHC experiments have, so far, measured many of the Higgs couplings and found excellent agreement with the minimally-realized electroweak symmetry breaking (EWSB) mechanism in the Standard Model. Nevertheless, there are important couplings that are currently out of reach which test the nature of EWSB and fermion mass generation. This talk will focus on two of them: the charm Yukawa and the hhVV couplings. A measurement of the first would confirm that the 125 GeV Higgs which gives mass to third generation fermions also gives mass the second generation. To this end, I will describe recent ideas to probe the charm Yukawa coupling in particular by using Higgs differential distributions. In the second case, deviations of the hhVV coupling from the SM would signal non-linearity and herald new physics at higher energies. As I will show, double Higgs production in VBF at the LHC can provide such a test at the 20% level by the end of the high luminosity run while a percent level constraint can be obtained at a future circular collider.

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10/02/2017 Mercedes Paniccia (Geneva)

The Alpha Magnetic Spectrometer on the International Space Station: the era of precision cosmic-ray physics

The Alpha Magnetic Spectrometer (AMS) is the most powerful and sensitive cosmic-ray detector ever deployed in space to produce a complete inventory of charged particles and nuclei in cosmic rays near Earth in the energy range from GeV to few TeVs. Its physics goals are the study of cosmic-ray properties, indirect search for Dark Matter and direct search for primordial antimatter. The improvement in accuracy over previous measurements is made possible through its long duration time in space, large acceptance, built in redundant systems and its thorough pre-flight calibration in the CERN test beam. These features enable AMS to analyse the data to an accuracy of ~1%. Since its installation on the International Space Station in May 2011, AMS has collected more than 90 billion cosmic-ray events and has produced precision measurements of electron, positron, proton, antiproton, He and light nuclei fluxes and of their ratios in cosmic rays of energy ranging from GeV to few TeVs. The percent precision of the AMS results challenges the current understanding of the origin and of the acceleration and propagation mechanisms of cosmic rays in the galaxy and thereby requires new theories to be developed by the physics and astrophysics community. In this talk, after a brief introduction to cosmic-ray physics, I will present the latest AMS results based on its first five years of data taking, pointing out their implication for cosmic-ray modelling and for Dark Matter searches.

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27/01/2017 : Jan Kretzschmar (Liverpool)

Precision W and Z cross-sections and the first measurement of the W boson mass at ATLAS

The Large Hadron Collider has produced more W and Z bosons than any other collider before. The large samples of leptonic bosons decays provide a unique opportunity for precision studies of the strong interaction and the electroweak interaction. These studies are facilitated by the high experimental precision achieved in these measurements after a careful detector calibration. New cross-section measurements allow novel insights into the proton structure. Specifically, strong constraints of the poorly known strange-quark distribution are demonstrated in a NNLO QCD analysis. The mass of the W boson is a key parameter in the global electroweak fit to test the overall consistency of the Standard Model. The first complete W-boson mass measurement at the LHC is presented, which requires an extraordinary control over both experimental and theoretical effects.

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20/01/2017 Jon Butterworth (UCL)

Making measurements and constraining new physics at the LHC

Particle-level differential measurements made in fiducial regions of phase-space at colliders have a high degree of model-independence. These measurements can therefore be compared to BSM physics implemented in Monte Carlo generators in a very generic way, allowing a wider array of final states to be considered than is typically the case. A new method providing general consistency constraints for Beyond-the-Standard-Model (BSM) theories, using measurements at particle colliders, is presented.

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09/01/2017 Jordan Myslik (LBNL) NOTE: UNUSUAL DATE/PLACE!!! Physics E7

The MAJORANA DEMONSTRATOR

Abstract: The MAJORANA DEMONSTRATOR is an experiment searching for neutrinoless double-beta decays of germanium-76. This lepton-number-violating process is connected to the nature, absolute scale, and hierarchy of the neutrino masses. The MAJORANA DEMONSTRATOR consists of two modular arrays of natural and 76Ge-enriched germanium detectors totalling 44.1 kg, located on the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota. While seeking to demonstrate backgrounds low enough to justify a tonne-scale experiment and the feasibility of its construction, the MAJORANA DEMONSTRATOR's ultra-low backgrounds and excellent energy resolution also allow it to probe additional physics beyond the Standard Model. This talk will discuss the physics and the design elements of the MAJORANA DEMONSTRATOR, its results to date, and its future prospects, along with the plans for a future 1 tonne germanium-76 neutrinoless double-beta decay experiment.

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16/12/2016 Eric Jansen (CMCC)

Numerical ocean modelling and the case of MH370

In this seminar I will take you on a small excursion into the world of numerical ocean modelling, and more specifically: data assimilation. The field of ocean data assimilation is concerned with updating ocean forecasts using daily observations of the ocean state in order to produce more accurate forecasts for the next day. Observations are incredibly diverse: buoys and moorings that measure time-series in a specific location, autonomous vehicles that can dive and resurface, coastal radar systems that measure currents, but also satellite measurements of the sea surface. I will discuss how we can assimilate these observations using a Kalman filter technique, applied to an ensemble of ocean model realisations. The second part of the seminar will focus on how we can apply these ocean models to a real-world problem: the disappearance of flight MH370. Malaysia Airlines flight 370 was a commercial flight from Kuala Lumpur to Beijing, which vanished without a trace in March 2014. It is believed to have crashed somewhere off the west-coast of Australia, but despite extensive search operations the main wreckage was never found. Now, more than two years later, parts belonging to the aircraft are found 4000km away on the African coast. How can we use this information to locate the crash site?

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NOTE UNUSUAL DAY!: 14/12/2016 Prof. Un-Ki Yang (Seoul National Univ.) 4pm, UNUSUAL LOCATION: E7

Searches for heavy neutrinos at the LHC

Heavy neutrinos occur in various extensions of the Standard Model (SM) and may explain the observed small masses of the SM neutrinos via several possible variants of the seesaw mechanism. We present results on searches for heavy neutrinos at the LHC. Searches are performed in the dilepton+jets channel and the trilepton channel, and results are interpreted in terms of the Left-Right Symmetrical model, Type-I, and the Type-III seesaw mechanism.

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02/12/2016 Clare Burrage (Nottingham)

Detecting Dark Energy with Atom Interferometry

I will discuss the possibility that the nature of the dark energy driving the observed acceleration of the Universe on giga-parsec scales may be determined first through metre scale laboratory based atom interferometry experiments. I will begin by discussing why our attempts to solve the cosmological constant problem lead to the introduction of new, light degrees of freedom. In order to be compatible with fifth force constraints these fields must have a screening mechanism to hide their effects dynamically. However, this doesn’t mean that they are impossible to detect. I will discuss the constraints that arise from a range of laboratory experiments from precision atomic spectroscopy to collier physics. Finally I will show that atom-interferometry experiments are ideally suited to detect a large class of the screening mechanisms known as chameleon. This will then allow us to either rule out large regions of the chameleon parameter space or to detect the force due to the dark energy field in the laboratory.

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25/11/2016 Lucian Harland-Lang (UCL))

Photon-photon collisions at the LHC

I will discuss the possibilities for using the LHC as a photon colliding machine. The colour singlet nature of the photon means that it can readily lead to exclusive or semi-exclusive events, with limited or no extra particle production in the final state. I will show how such processes provide a well understood environment in which to test the Standard Model and search for BSM physics. This is particularly relevant at the LHC, where these events may be selected using dedicated 'proton tagging' detectors installed in association with ATLAS and CMS. I will also consider the impact of photon-initiated processes on the more common inclusive production modes at the LHC. Here, the photon must be included in addition to the quarks and gluons as a parton in the proton. I will demonstrate that, despite indications to the contrary from earlier studies, the photon parton density in the proton is in fact quite precisely known, and consider the implications for LHC (and FCC) phenomenology.

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18/11/2016 James Currie (IPPP Durham)

Jet Production at NNLO

Jet production is one of the most ubiquitous yet important reactions at the LHC. Calculating higher order corrections to this observable allows us to gain sensitivity to phenomenological parameters such as the strong coupling and the gluon PDF as well as providing a rigorous test of QCD over a vast kinematic range. It is well known that calculating higher order corrections is a non-trivial task and requires a powerful method to subvert the various infrared singularities present in the calculation. I will introduce the Antenna Subtraction method as a means of calculating finite cross sections and present some recent results obtained by applying this method to the problem of jet production at NNLO.

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11/11/2016 Marcel Vos (IFIC Valencia))

Future of top Physics

In this seminar I discuss the potential of planned facilities - lepton and hadron colliders - to bring our understanding of the top quark to the next level. The focus is on measurements of top quark properties and interactions with exquisite sensitivity for signals of the physics that lies behind the Standard Model: the top quark mass measurement, the search for FCNC interactions involving top quarks and those characterizing the top quark couplings to the gluon, EW gauge bosons and the Higgs boson. The precision that new experiments can achieve in these key measurements is compared to the current state-of-the-art and the expectation for the complete LHC programme.

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04/11/2016 Marco Pappagallo (University of Bari & INFN)

exotic hadronic states in LHCb (Penta/Tetra quarks)

The latest years have seen a resurrection of interest in searches for exotic states. Using the data collected at pp collisions at 7 and 8 TeV by the LHCb experiment, unambiguous new observations of exotic charmonia hadrons produced in B and Lambdab decays are presented. Results of a search for a tetraquark state decaying to Bs pi+- are reported as well

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28/10/2016 Jeff Foreshaw(Manchester) NOTE: earlier time: 3pm! different room: E7!

“Probabilities and Signalling in Quantum Field Theory”

I will talk about a way to compute transition probabilities that works directly that the level of probabilities and not amplitudes. The formalism guarantees that the initial and final states are always linked by a chain of retarded propagators and it has a nice diagrammatic approach.

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26/10/2016 NOTE time and place!

Gravitational Wave Symposium

26th October 14.00 Imperial College London, Blackett Laboratories LT1 lecture theatre
A half day physics meeting on gravitational waves. Leading scientists from the Astro and HEP communities will present the recent discovery of gravitational waves and future prospects of this new field in fundamental physics. The talks are aimed at interested researchers at all levels across all of London's universities. See: https://indico.cern.ch/event/563302

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21/10/2016 2nd year PhD Students, NOTE different time/place!

2nd year PhD talks!

1pm-5pm in E3/E7

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14/10/2016 Sally Shaw (UCL)

The LUX & LZ Dark Matter Experiments: WIMP Hunting in the Black Hills

Discovery of the nature of dark matter is recognised as one of the greatest contemporary challenges in science, fundamental to our understanding of the universe. Weakly Interacting Massive Particles (WIMPs) that arise naturally in several models of physics beyond the Standard Model are compelling candidates for dark matter. The LUX experiment, operated 1.5 km underground in the Davis Cavern of the SURF laboratory, USA, is the world leader in the direct hunt for WIMPs. I will present the latest LUX results and describe the unique in-situ calibrations that have allowed low energy nuclear recoil measurements in liquid xenon, greatly enhancing our sensitivity to low mass WIMPs. I will also discuss the status of LUX’s multi-tonne successor, LZ, demonstrating how its sensitivity is ideally matched to explore the bulk of the remaining theoretically favoured electroweak phase space towards galactic dark matter discovery.

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07/10/2016 Leszek Roszkowski (Sheffield and NCBJ)

Particle dark matter: what it is and how to determine its properties

After a brief introduction I will comment on some recently discussed WIMP candidates for dark matter. In particular, I will provide arguments that a supersymmetric neutralino with mass around 1 TeV and well defined properties has emerged as an attractive and experimentally testable candidate for dark matter in light of measured Higgs boson properties and ensuing implications for supersymmetry searches at the LHC. On the other hand, for a wide range of WIMPs, and independent of any specific particle physics scenarios, when a dark matter signal is eventually measured in direct or indirect search experiments, or both, it may prove rather challenging to work out ensuing WIMP properties.

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19/07/2016 Mark Scott (TRIUMF)

T2K and NuPRISM: An experimental solution to the problems of neutrino interactions in long baseline neutrino experiments

T2K is a long baseline neutrino experiment in Japan that has published world-leading measurements of neutrino oscillations and has the potential to find evidence of CP violation in the lepton sector. The first half of this talk will give a brief description of neutrino oscillations before presenting the latest neutrino oscillation results from the T2K experiment. The difficulties of neutrino interaction modelling and how this affects oscillation analyses will be discussed before introducing the NuPRISM detector. NuPRISM is an intermediate water Cherenkov detector that continuously samples the neutrino beam across a range of off-axis angles. This detector can remove the problems associated with neutrino interactions by recreating the oscillated far detector spectrum using near detector data. The second half of the talk will describe the NuPRISM analysis method, highlighting the unique abilities of the detector and will present an oscillation analysis that is insensitive to incorrect neutrino interaction modelling.

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1/07/2016 Srubabati Goswami (Physical Research Laboratory, Navrangpura, Ahmedabad)

Probing the Leptonic CP violation in current and future experiments

In this talk I will summarize the current status of the CP phase in the lepton sector. I will discuss the main difficulties associated with the measurement of this parameter. In particular I will discuss the problem of parameter degeneracies. How the synergy between beam based and atmospheric neutrino experiments can help in the determination of the CP phase will be shown. I will also discuss the sensitivity of the DUNE experiment to measure this parameter.

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17/06/2016 Andreas Korn (UCL)

Impressions from DM@LHC2016

I will give my personal impressions from the Dark Matter workshop DM@LHC2016. Slides from my own talk, titled "Latest results in the mono-jet and di-jet channels" will be reused and augmented by selected highlights from a spectrum of other talks.

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10/06/2016 Suchita Kulkarni (HEPHY Viena)

Impact of LHC monojet searches on new physics scenarios

Dark matter searches at the LHC are exploring new models and new regime with every new result. I take a specific example of monojet dark matter searches at the LHC and sketch their impact on two dark matter scenarios. I discuss the complementarity of the results with the direct and indirect detection searches. The two models under considerations are, dark matter motivated explanations of the 750 GeV diphoton excess and dark matter interactions with the Standard Models involving derivative couplings.

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03/06/2016 Miguel Arratia (Cambridge)

"Inelastic proton-proton cross-section at 13 TeV with ATLAS,

The inelastic proton-proton cross-section is a basic property of proton interactions, yet it cannot be calculated from first principles. In 1973 experiments at CERN discovered that it rises with energy—as Heisenberg had predicted. Today, the LHC sets the energy frontier at 13 TeV, and theory predicts an asymptotic “black-disk” limit. In this seminar, I will present a recent measurement of the inelastic cross-section with the ATLAS detector. One of the key ingredients for this study is the rate at which the LHC produces proton collisions—the luminosity. I will illustrate how we measure the LHC luminosity and achieve a percent-level accuracy. Finally, I will describe how this result relates to one of the open questions in cosmic ray physics. "

[slides]

27/05/2016 Heidi Sandaker (Oslo)

“The AEGIS experiment”

The AEGIS experiment, situated at the Antimatter Decelerator (AD) at CERN aim to measure for the first time the Earth’s gravitational acceleration of anti-Hydrogen. To achieve this the AEGIS collaboration plan to produce a pulsed cold anti-Hydrogen beam and send it through a classical Moire deflectometer before the anti-Hydrogen is detected by a system of position sensitive detectors. Beyond the gravitational measurements, AEGIS will also provide long-term anti-matter spectroscopy measurements. This talk will present both the scope and current status of the AEGIS experiment as well as discuss future measurements.

[slides]

13/05/2016 Kazuki Sakurai (Durham)

“Search for Sphalerons: LHC vs. IceCube"

In a recent paper, Tye and Wong (TW) have argued that sphaleron-induced transitions in high-energy interactions should be enhanced compared to previous calculations, based on a construction of a Bloch wave function in the periodic sphaleron potential and the corresponding pass band structure. In this talk, I present our resent work studying future prospects of observing sphaleron transitions at high energy hadron colliders and IceCube, based on TW results. I first discuss the production rate and possible signatures of the sphaleron-induced processes at high energy hadron colliders. We recast the early ATLAS Run-2 search for microscopic black holes to constrain the rate of sphaleron transitions at 13 TeV LHC. In the second half of the talk, I will discuss the possibility of observing sphaleron transitions induced by cosmogenic neutrinos at IceCube. I calculate the sphaleron event rate at IceCube and discuss the signature of such events. Finally I compare the performance of the sphaleron searches at the LHC and IceCube and find complementarity of these experiments.

[slides]

06/05/2016 David Hesketh (Tradinghub)

Financial Rogue Trading and Market Abuse – Finding the Signal in the Noise

The actions of Jerome Kerviel and Kweku Adobole resulted in billion dollar losses for SocGen and UBS. Similarly, the FX and LIBOR scandals have seen banks fined in the hundreds of millions of dollars. This presentation asks why the banks struggle to identify the signals left by these traders. Topics covered include what the traders were doing in each case, the big data statistical approaches used by the anti-terrorist sections of the CIA and MI5 that have been co-opted by the banks and the unique statistical performance metrics used by TradingHub to solve the problem.

The amount of data from various sources: intelligence networks, traffic monitoring, social media, mobile phones, genomics, health etc) data now available for analysis has increased substantially in the last couple of years. However at the same time the requirements on the privacy of the underlying data have become more stringent requiring the need for algorithms to be developed that preserve the privacy of the underlying data while still extracting information with value (economic and otherwise). In this talk the algorithms and methodology being deployed by Privatar will be described.

Jason Mcfall (Privitar)

Privacy in the age of data science

The collection of vast data sets, and the availability huge compute power to analyse them, brings striking new threats to individual privacy. I'll talk through some of the risks and examples of privacy breaches, and survey some promising techniques for protecting data privacy by statistical means, and talk about why this is a hard problem to solve.

[slides]

15/04/2016 Richard Amos (UCL/UCLH)

Targeting cancer with proton beams: developments at UCL Hospital

Proton beam therapy (PBT) offers potential clinical advantages over conventional radiotherapy for cancer due to the physical characteristics of charged particle interaction. As protons traverse patient anatomy they lose energy, becoming more densely ionising as they approach their end-of-range, at which point they stop. This manifests into dose deposition as a function of depth that increases to a maximum, the Bragg peak, towards their end-of-range, with no dose beyond. By choosing proton beams of initial energy such that the Bragg peak region is delivered at the depth of the clinical target volume, the therapeutic dose can be realized with reduced dose to surrounding healthy tissue compared to that delivered by photons. Reduced dose to surrounding tissue offers the potential for reduced acute toxicity and secondary cancer risk. These potential clinical advantages have led to a rapid growth in availability of PBT worldwide in recent years and such capability will soon be available at UCL Hospital (UCLH) for NHS patients indicated for protons.

This presentation will describe contemporary PBT technology and practice with particular emphasis given to recent developments and the current status of the UCLH PBT project.

[slides]

08/04/2016 Nick Ryder (Oxford)

A SoliD seminar: The SoLid experiment: searching for neutrino oscillations within 10 m from a nuclear reactor

The SoLid collaboration aim to solve the reactor neutrino anomaly by determining whether it is due to oscillations to a new type of `sterile' neutrino. By measuring the anti-neutrino flux as a function of energy and distance between 5 and 10 m from a reactor core, a direct search for oscillations can be performed without relying on flux calculations. I will explain the reactor anomaly and other motivations for our experiment from unexpected structure in the reactor flux spectrum and nuclear safeguards. Performing a neutrino experiment so close to a reactor core presents a number of challenges. I will explain these challenges and the novel, highly segmented, composite scintillator anti-neutrino detector we have developed to overcome them. I will discuss the prototype detectors that we have built and our plans for a phased deployment of our full scale detector starting later this year.

[slides]

POSTPONED! now: 15/04/2016 Richard Amos (UCL/UCLH)

Targeting cancer with proton beams: developments at UCL Hospital

Proton beam therapy (PBT) offers potential clinical advantages over conventional radiotherapy for cancer due to the physical characteristics of charged particle interaction. As protons traverse patient anatomy they lose energy, becoming more densely ionising as they approach their end-of-range, at which point they stop. This manifests into dose deposition as a function of depth that increases to a maximum, the Bragg peak, towards their end-of-range, with no dose beyond. By choosing proton beams of initial energy such that the Bragg peak region is delivered at the depth of the clinical target volume, the therapeutic dose can be realized with reduced dose to surrounding healthy tissue compared to that delivered by photons. Reduced dose to surrounding tissue offers the potential for reduced acute toxicity and secondary cancer risk. These potential clinical advantages have led to a rapid growth in availability of PBT worldwide in recent years and such capability will soon be available at UCL Hospital (UCLH) for NHS patients indicated for protons.

This presentation will describe contemporary PBT technology and practice with particular emphasis given to recent developments and the current status of the UCLH PBT project.

11/03/2016: IOP Practise TALKS!

3rd years!

Exciting new results!

09/03/2016 Prof. Chris Done (Durham University)

XXVI SPREADBURY LECTURE: Black Holes - Science fact, fiction or fantasy ?

Black holes are a key plot device in science fiction and fantasy: wormholes through space and time ! In this lecture I'll separate out the fact from the fiction, and talk about how black holes went from a speculative extension of Einstein's gravity to a mainstream observational science via the development of rockets at the start of the space age.

26/02/2016: Chiara Casella (Geneva)

The SAFIR (Small Animal Fast Insert for mRi) experiment

SAFIR - Small Animal Fast Insert for mRi - is a non conventional positron emission tomography (PET) detector for fast and simultaneous hybrid PET/MRI imaging on small animals. The PET detector is designed specifically to be used inside the bore of a commercial 7T pre-clinical magnetic resonance scanner and with ultra short acquisition durations of the order of a few seconds, to enable quantitative dynamic studies of fast biological processes (e.g. blood perfusion and cerebral blood flow with 15O tracers). To compensate for the statistics losses due to the short scan durations, SAFIR will use up to 500 MBq injected activities, one order of magnitude increase with respect to state-of-the-art preclinical systems. Beside the clear MR compatibility, severe important challenges have to be met by the SAFIR detector, mainly in terms of spatial resolution, timing resolution and sensitivity, high number of readout channels, high rate capability per channel and huge data throughput. The detector will rely on matrices of L(Y)SO crystals, optically coupled to SiPM arrays and readout by existing fast readout ASICs. The seminar will describe the SAFIR goal, its concept and the status of the project, with particular emphasis on the characterization measurements of the detector components, including the recent high rate tests performed with different ASICs for the SiPM readout.

[slides]

19/02/2016 Uli Haisch (Oxford)

Indirect probes of Higgs effective theory

I review the existing indirect constraints on Wilson coefficients entering the Higgs effective theory. These limits are compared to the direct bounds obtained from LHC and LEP physics.

[slides]

12/02/2016 Katharina Bierwagen (MIT)

Measurement of inclusive W/Z production cross sections and CMS performance at sqrt(s)=13 TeV

Precise measurements of W and Z boson production provide an important test of the SM and can be used to further constrain the Parton Distribution Functions. The production of W and Z bosons is well understood in the SM and the clean signatures of the decay particles provide an ideal test bench for the commissioning of the electron, muon and missing energy reconstruction algorithms in the LHC environment. The first results of inclusive W and Z production cross section measurements in pp collisions at sqrt(s)=13 TeV with the CMS detector are presented.

[slides]

5/02/2016 Will Barter (CERN)

Recent LHCb measurements of electroweak boson production in Run-1

We present the latest LHCb measurements of forward Electroweak Boson Production using proton-proton collisions recorded in LHC Run-1. The seminar shall discuss measurements of the 8 TeV W & Z boson production cross-sections. These results make use of LHCb's excellent integrated luminosity determination to provide constraints on the parton distribution functions which describe the inner structure of the proton. These LHCb measurements probe a region of phase space at low Bjorken-x where the other LHC experiments have limited sensitivity. We also present measurements of cross-section ratios, and ratios of results in 7 TeV and 8 TeV proton-proton collisions. These results provide precision tests of the Standard Model.

The seminar shall also present a measurement of the forward-backward asymmetry (A_FB) in Z boson decays to two muons. This result allows for precision tests of the vector and axial-vector couplings of the Z boson, providing sensitivity to the effective weak mixing angle (sin^2(theta_W^eff)). The A_FB distribution visible in the LHCb acceptance is particularly sensitive to this angle, as the forward phase-space means that the initial state quark direction is better known than in the central region. This reduces theoretical uncertainties in extracting sin^2(theta_W^eff) from A_FB, and allows LHCb to make the currently most precise determination of sin^2(theta_W^eff) at the LHC.

[slides]

22/01/2016, Prof. Andre Schoening (Heidelberg)

The Mu3e Experiment

The Mu3e experiment will search for the Lepton Flavour violating decay mu^+ -> e^+ e^+ e^- with unprecedented sensitivity of 1 out of 10^16 muon decays. This process is heavily suppressed in the Standard Model and any signal would be a clear sign of new physics. The Mu3e experiment is based on the new HV-MAPS detector technology which allows to build ultra-light and fast high resolution pixel detectors.

15/01/2016 Ben Allanach (Cambridge)

Anatomy of the ATLAS diboson excess

I shall discuss some measurements from 8 TeV Run I LHC data that showed an excess over 2 sigma with respect to Standard Model expectations. In particular, we shall review the ATLAS di-boson excess, and show a couple of new physics scenarios that explain the excess. If there is time, I shall then discuss some excesses in CMS data: in a W_R search, in a di-leptoquark search and a new physics explanation that has implications for neutrinoless double beta decay.

[slides]

11/12/2015 Dr. Juan Rojo (Oxford)

Reduction strategies for the combination of PDF sets and the PDF4LHC15 recommendations

We discuss recently developed strategies for the statistical combination of PDF sets. These methods allow to combine the predictions of many different PDF sets into a single combined set, in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas. These combination strategies have been used for the implementation of the 2015 PDF4LHC recommendations, required for the estimation of the total PDF+alphas uncertainties for LHC cross-sections at Run II. We discuss the improvements as compared to the 2011 PDF4LHC prescription, and the impact of the new prescription on precision measurements at Run II.

[slides]

04/12/2015 Dr. Sofiane Boucenna (Frascati)

Common Frameworks for DM and Baryogenesis

The nature of dark matter (DM) and the origin of the baryon asymmetry of the Universe (BAU) are two enduring mysteries in particle physics and cosmology. Many approaches have been developed to tackle them simultaneously leading to diverse models and paradigms, such as Asymmetric dark matter (ADM). In the first part of the talk I will give a (brief) overview of what has been done so far, highlighting the important concepts of these constructions. Then, in the second part, I will present a new framework relating the weakly interacting massive particles paradigm to ADM in a minimal and model-independent way.

[slides]

27/11/2015 Frank Tackmann (DESY)

XCone: N-jettiness as an Exclusive Cone Jet Algorithm

I will discuss a new jet algorithm XCone, which is based on minimizing the event shape N-jettiness and has several attractive features. It is exclusive and always returns a given fixed number of jets. Well-separated jets are conical and practically identical to anti-kT jets of the same size. Overlapping jets are automatically partitioned by nearest-neighbor. In this way, XCone allows to smoothly transition between the resolved regime where all jets are well separated and the boosted regime where they overlap. It also inherits the theoretical factorization properties of the underlying N- jettiness variable. I will show examples of its application for dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs.

[slides]

20/11/2015 Katharine Leney (UCL)

Searching for Di-Higgs→bbττ at ATLAS

Several models for new physics predict TeV scale resonances that decay to pairs of Higgs bosons. This talk will review the ATLAS search for pair-produced Higgs bosons decaying to bbττ final states using 20 fb-1 proton-proton collision data with √s = 8 TeV and present the combination of all Run 1 ATLAS di-Higgs searches. I will also review the prospects for di-Higgs searches in the bbττ channel for Run 2 and beyond.

[slides]

13/11/2015 Geoff Hall (Imperial)

Tracking and trigger upgrades of CMS

CMS will upgrade its trigger during the forthcoming 13 TeV run to maintain performance under increasingly challenging pileup conditions due to the success of the LHC machine in delivering high luminosity collisions. In the longer term, a new tracker is proposed for installation around 2023, which will for the first time provide data to be used in the L1 trigger. LHC data taking is expected to continue until well into the 2030 decade. The motives for these developments and progress towards them will be explained.

[slides]

06/11/2015 Sarah Malik (Imperial)

Review of the status and future prospects of dark matter searches at colliders

Understanding the nature of dark matter is one of the most compelling, long standing questions in physics. Reports of possible dark matter signals from several direct detection experiments have further highlighted the need for independent verification from non-astrophysical experiments, such as colliders. I will review the results of searches for dark matter at CMS in Run 1 of the LHC, what we can expect in Run 2 and beyond, as well as recent developments in dark matter phenomenology.

[slides]

30/10/2015 Doug Cowen (Penn State)

High Energy Atmospheric Neutrino Appearance and Disappearance with IceCube

The IceCube neutrino observatory, buried deep in the ice at the South Pole, has detected neutrinos that span over five orders of magnitude in energy. Fulfilling one of its original stated goals of discovering cosmological ultrahigh energy neutrinos, its large instrumented volume also provides us with a surprisingly powerful instrument for studying neutrino oscillations with an unprecedented statistical sample of energetic atmospheric neutrinos. In this presentation we will describe the IceCube detector and focus on its current and future atmospheric neutrino oscillation measurements with DeepCore, IceCube's low-energy in-fill array. We will also describe a new proposed low-energy extension, the Precision IceCube Next Generation Upgrade (PINGU), highlighting its ability to measure one of the remaining fundamental unknowns in particle physics, the neutrino mass hierarchy.

[slides]

23/10/2015 Gavin Hesketh (UCL) UNUSUAL PLACE/TIME
16.15 Auditorium XLG2 | Christopher Ingold Building

Life after the Higgs: Where next for particle physics?

The Large Hadron Collider, the world's largest particle accelerator, recently restarted after a 2 year break. Smashing protons together at almost twice the energies previously achieved, the data taken next few years may reveal more about the fundamental building blocks of the universe. But, with the discovery of the Higgs Boson in 2012, the theory of these building blocks, the Standard Model, was "completed". So what could we hope to learn next, either at the LHC or elsewhere? http://events.ucl.ac.uk/event/event:hbc-icokdek5-siapwd/life-after-the-higgs-where-next-for-particle-physics

[slides]

16/10/2015 Louis Lyons (Oxford/Imperial)

“Statistical Issues in Searches for New Physics

Given the cost, both financial and even more importantly in terms of human effort, in building High Energy Physics accelerators and detectors and running them, it is important to use good statistical techniques in analysing data. This talk covers some of the statistical issues that arise in searches for New Physics. They include topics such as:

  • Blind analyses
  • Significance
  • Should we insist on the 5 sigma criterion for discovery claims?
  • $P(A|B)$ is not the same as $P(B|A)$.
  • The meaning of $p$-values.
  • Example of a problematic likelihood.
  • What is Wilks' Theorem and when does it not apply?
  • How should we deal with the `Look Elsewhere Effect'?
  • Dealing with systematics such as background parametrisation.
  • Coverage: What is it and does my method have the correct coverage?
  • Combining results, and combining $p$-values
  • The use of $p_0$ v $p_1$ plots.
This is an extended version of a talk given at the LHCP2014 Conference in New York in June 2014.

[slides]

09/10/2015 Linda Cremonesi (UCL)

Neutrino interactions at the T2K near detector complex

The T2K long-baseline neutrino oscillation experiment observed electron neutrino appearance in 2011 and reported the first results of a search for electron anti-neutrino appearance in 2015. Systematic uncertainties relating to the models of neutrino interactions on atomic nuclei are increasingly problematic as the precision of oscillation measurements improves. Interaction cross-section measurements are therefore vital for the correct interpretation of neutrino data, and consequently reducing the uncertainties on the oscillation measurements. The near detector complex of T2K, with scintillating tracking detectors on-axis (INGRID) and a magnetised fine-grained tracking system off-axis (ND280), offers a unique opportunity to study neutrino interactions in the region of 0.6~1GeV. In this seminar I will report the latest cross-section measurements performed at ND280 and INGRID, which include muon neutrino charged current interactions on different targets (scintillator or water) and with various final states (inclusive, zero pion, one pion and coherent pion production). I will illustrate the value of this data and the difficulties that still remain.

[slides]

27/08/2015 Foteini Oikonomou (Penn State)

Note: Unsual time/date 2pm:
A multi-messenger quest for the sources of the highest energy cosmic rays

The sources of cosmic rays with energy exceeding 10^18 electron volts remain unknown, despite decades of observations. The discovery of the sources of these fascinating cosmic messengers, termed ultra-high energy cosmic rays (UHECRs), will unravel the workings of the Universe's most violent accelerators. I will discuss the constraints imposed by UHECR observations on their sources, focusing on the arrival direction distribution of the UHECRs detected at the Pierre Auger observatory. Constraints on the sources of UHECRs are also imposed by observations of the secondary particles (gamma-rays and neutrinos) that UHECRs produce during their propagation in the intergalactic medium. By way of illustration, I will present models of UHECR emission in blazars, and discuss the detectability of the signatures of such (hadronic) processes in blazar gamma-ray spectra. Finally, I will present the current status of experimental efforts to pin down the origin of UHECRs, by detecting UHECR, neutrino, and electromagnetic transient emission, through real-time coincidence searches, within a global, multi-messenger, alert network.

[slides]

19/06/2015 : Diego Aristizabal (Université de Liège)

Neutrino masses beyond the tree level

The standard approach to Majorana neutrino masses relies on the type-I seesaw, where neutrino masses are induced through tree level exchange of heavy right-handed neutrinos. Other scenarios, however, are possible and they typically offer testable predictions and in some cases even connections with dark matter. In this talk, after reviewing some well-known loop-induced neutrino mass models, I will discuss a generic approach for two-loop-induced neutrino masses. Finally, I will comment on some possible "generic" accelerator tests of these scenarios.

[slides]

12/06/2015 : Alex Martyniuk (UCL)

Search for diboson resonances at ATLAS using boson-tagged jets

With the advent of 13TeV proton-proton collisions at the LHC it is natural to trawl through this data searching for new resonances with the highest possible masses. Do we have any clues of what we might expect in this new energy regime? An ATLAS paper released in the dying moments of LHC Run-1* offers us a possible direction. This paper describes a search for a heavy resonance (either a W’ or Kaluza-Klein Graviton) decaying into a diboson pair, leading to highly boosted hadronic jets. By exploiting jet substructure techniques to pick the signal out of the dominant QCD backgrounds the analysis can take advantage of the high branching fraction enjoyed by the fully hadronic decay channel. In this seminar I will describe the jet-substructure techniques explored by the analysis, present the results of the analysis of the 20fb^-1 of 8TeV ATLAS data and finally look to the prospects with the new collision data.

[slides]

05/06/2015 : Yue-Lin Sming Tsai (IPMU)

Singlet Majorana fermion dark matter: LHC14 and ILC

Exploring a dark matter (DM) candidate using an effective field theory (EFT) framework is a popular approach. However, since the central energy of LHC is going to be 14 TeV and future ILC experiment could also reach 1 TeV, the EFT is not valid any more. In this talk, I will first review our previous work, 1407.1859, then show how we conservatively estimate the power LHC&ILC on EFT by comparing with the UV completed model.

[slides]

29/05/2015 Ben Cooper/David Wardrope (UCL)

Searching for new physics with di-Higgs to 4b final states at ATLAS.

It is not often these days that a completely new channel is developed to search for evidence of new physics at the LHC. When Run-1 of the LHC began, the general consensus was that, compared to final states containing leptons, fully hadronic final states would not be competitive in the search for new physics, because the enormous QCD backgrounds would be overwhelming. In this seminar we will tell the story of how this notion was reversed for Higgs pair production, present the latest Run-1 results of the di-Higgs to 4b searches by ATLAS and CMS, and give the prospects for exploiting this channel in the future, including the potential for dramatically extending the physics reach of the HL-LHC.

[slides]

22/05/2015, Leigh Whitehead (UCL) NOTE UNUSUAL TIME: 12.30 !!!

The CHIPS Experiment

CHIPS (Cherenkov Detectors In mine PitS) is an R&D project aiming to blaze the trail towards affordable megaton scale neutrino detectors whilst contributing to the world knowledge on the neutrino mass hierarchy and delta_cp. The first step on the way to this goal was the deployment of CHIPS-M, a small prototype in an open mine pit in northern Minnesota, exposed by the NuMI beam from Fermilab. The second 10 kton prototype, CHIPS-10, is in the design process and is due for deployment in the summer of 2016. CHIPS-10 combined with NOvA and T2K will give over three sigma sensitivity to the mass hierarchy and delta_cp. I will give an overview of the experiment, show the first data from CHIPS-M, and discuss the design of CHIPS-10 and our plans for the future.

15/05/2015, Josef Pradler (HEPHY Vienna)

Dark Vectors in Cosmology and Experiment

More often than not, astrophysical probes are superior to direct laboratory tests when it comes to light, very weekly interacting particles, and it takes clever strategies and/or ultra-pure experimental setups for direct tests to be competitive. In this talk, I will highlight this competition on the example of dark photons. When they are dark matter, direct detection probes can be superior to stellar constraints. When they decay, cosmology offers unique sensitivity through BBN and CMB.

[slides]

30/04/2015 note: unusual DATE: Alain Blondel (Geneva)

CERN: the next 60 years and 100 kilometers

CERN is hosting the design study of Future Circular Colliders fitting in a new tunnel of 100km circumference around Geneva. A possible first step is the "Electroweak Factory", a high luminosity electron-positron (lepton) collider covering the energy range from the Z pole to above the top threshold, for the study of several TeraZ, okuW, MegaHiggs and Megatops. The tunnel would fit, as ultimate goal, a 100 TeV pp collider. The project will be described with special attention to the electron machine. The combination of the two machines offers a remarkable potential for discoveries, from a blend of precision measurements, high statistics, high energies and sensitivity to very small couplings. In particular the search for sterile right-handed neutrinos (aka neutral heavy leptons), with mass up to the Z mass, will be shown to reach couplings as small as predicted by the see-saw limit.

[slides]

17/04/2015 Deepak Kar (Glasgow/TBC)

All about showering at the LHSea!

Improving the parton shower model in Monte Carlo generators is important for precision measurements as well as for searches at the LHC. ATLAS and CMS performed many interesting measurements sensitive to to non-perturbative QCD effects and compared the results with existing MC models and tunes, and clear discrepancies and new features have been observed in many cases. All these data are being used in improving the modelling. Also, many jet substructure techniques depend on modelling the shower accurately, and I will briefly discuss one such technique, called shower deconstruction, and the promising results it yields.

[slides]

10/04/2015 Cheryl Patrick (NorthWestern)

Neutrino-nucleus interactions at MINERvA

Fermilab's MINERvA experiment is designed to make precision measurements of neutrino scattering cross sections on a variety of materials. After introducing the MINERvA detector, I will explain why these measurements are so important to the current neutrino program. I will then describe several recently published results that are already being used by the neutrino community to improve their modelling of neutrino interactions, focusing particularly on the quasi-elastic analysis. There will also be a chance to look at interesting analyses that will be published in the coming months, and at the plans for MINERvA's longer-term future.

[slides]

27/03/2015 UCL HEP Students

IOP practise talks

Note unusual start time: 2pm

20/03/2015 Phillip Litchfield (UCL)

The AlCap experiment // A tour of muon physics from NuFact

The AlCap experiment is a joint project between the COMET and Mu2e collaborations. Both experiments intend to look for the lepton-flavour violating conversion μ+A→e+A, using tertiary muons from high-power pulsed proton beams. In these experiments the products of ordinary muon capture in the muon stopping target are an important concern, both in terms of hit rates in tracking detectors and radiation damage to equipment. The goal of the AlCap experiment is to provide precision measurements of the products of nuclear capture on Aluminium, which is the favoured target material for both COMET and Mu2e. The results will be used for optimising the design of both conversion experiments, and as input to their simulations. Time allowing, I will also present a (necessarily brief) tour of active and planned muon experiments, as presented at NuFact. The muon is something of a special case. Although we know there are three generations of Standard Model particles, the world around us is essentially built up from the first generation. The low mass and correspondingly long lifetime of the muon means that is one of very few higher-generation particles that can be manipulated for study, and as such provides a complimentary window to the standard 'brute force' approach of bringing first-generation particles together at ever higher energies and intensities. I will give a very brief summary of the muon projects discussed at NuFact 2014.

13/03/2015 Jennifer Jentzsch (Dortmund)

Quality assurance measurements during the ATLAS Insertable B-Layer production and integration

The ATLAS Detector is one of the four big particle physics experiments at CERN's LHC. Its inner tracking system consisted of a 3-Layer silicon Pixel Detector (~ 80M readout channels) in the first run (2010-2012) and has been upgraded by an additional layer over the last two years. The Insertable B-Layer (IBL) adds ~12M readout channels for improved vertexing, tracking robustness and b-tagging performance for the upcoming runs before the high luminosity of the LHC will take place. The active part of the detector is roughly 66cm long and consists of 14 parylene coated carbon foam support structures, so-called staves, at an average distance of 33.25mm away from the beam. The IBL includes new sensor and readout chip designs finding their first application in high energy physics experiments. Production accompanying measurements as well as preliminary results after integration into the ATLAS Detector, right before the start of the second LHC run, will be presented and discussed.

11/03/2015 : Jenny Thomas : 4pm Harrie Massey LT

XXV Spreadbury Lecture : Neutrino Oscillations At Work

The observation that the three types of neutrino flavour oscillate among themselves led to the realisation that neutrinos have a very small but non-zero mass. This is extremely important because the supremely successful Standard Model of particle physics had expected, and indeed needed, the neutrinos to have exactly zero mass. Since the discovery of neutrino oscillations over the last 15 years, the parameters of the oscillations have been sufficiently well measured to turn neutrino oscillations into a tool for learning more about the elusive neutrino. I will explain the concept of neutrino oscillations, and report on the recent results from around the world and the new challenges now facing researchers trying to infer the remaining unknown neutrino properties. I will talk briefly about an exciting new project on the horizon for the very near future.

06/03/2015 Freya Blekman (Brussels)

Exploring new physics in the Top quark sector using Beyond-Two-Generations Quarks with the Compact Muon Solenoid

In many models of physics beyond the Standard model the coupling of new physics to third generation quarks is enhanced or signatures are expected that mimic top production. I will present a review of mostly non-MSSM-inspired searches for new physics beyond the standard model in final states containing top quarks or bottom quarks performed by the CMS experiment. Many of these techniques used have solid roots in precision measurements of the standard model, and applying these techniques from measurements to searches has opened a rich and varied searches program in the CMS experiment. Examples include searches for heavy gauge bosons, excited quarks, sequential and vector-like top quark partners. The analyses span a range of final states, from multi-leptonic to entirely hadronic, and many use convoluted analysis techniques to reconstruct the highly boosted final states that are created in these topologies. I will focus on the recent results, using data collected with the CMS experiment in proton-proton collisions at the LHC at a centre-of-mass energy of 8 TeV.

[slides]

27/02/2015 Anastasia Basharina-Freshville (UCL)

Calorimetry for Cancer Proton Therapy - Can We Help?

Proton therapy is an advanced form of radiotherapy that provides significantly improved cancer treatment to patients. In Summer 2015 UCLH will commence the building of a 250 MeV proton beam treatment centre. Challenges currently exist in the field of proton therapy, such as the requirements of precise measurements of the beam energy and spread. We address some of these challenges using a calorimeter module designed for the SuperNEMO experiment, which we have tested at the only currently running proton treatment beam in the UK at the Clatterbridge Centre for Oncology.

[slides]

20/02/2015 Andrea Banfi (Sussex)

A general method for final-state resummations in QCD

We present a novel method that makes it possible to resum event-shape distributions and jet rates at NNLL accuracy. We present results for suitable observables in e+e- annihilation and discuss the generalisation of the method to hadron-hadron collisions and higher logarithmic accuracy.

13/02/2015 : Adam Gibson (UCL)

Tracking emissions during proton therapy

Proton radiotherapy uses a beam of protons at up to 250 MeV to deliver a dose of ionising radiation to the body, usually with the intention to cure cancer. The physics of proton interactions with tissue provides a particular advantage: most of the energy is deposited in the Bragg peak, meaning that deeper tissues are largely spared a substantial radiation dose. This reduces the likelihood of side effects, which include an increased risk of cancer later in life. Medical imaging provides excellent knowledge of the internal anatomy of the body, allowing the dose distribution to be precisely predicted. However, patient movement, weight loss and shrinkage of the tumour mean that imaging is not always sufficient to determine the dose distribution delivered. In this talk, I will discuss the physical interactions of the proton beam with tissue, particularly concentrating on the possibility of measuring x-ray, gamma, optical and acoustic emissions so as to predict in real time the distribution of radiation dose to the body.

[slides]

30/01/2015 Simon Bevan/John Loizides

From Particles to Electronic Trading

We will give a detailed overview of the exciting world of FX electronic trading (eFX), detailing the cutting edge technology and mathematics that drive the modern markets. Throughout we will highlight how the skills developed during our stint in HEP translated directly into eFX and why particle physicists are still in such demand.

[slides]

12/12/2014 : Teppei Katori (QMUL)

Liquid argon detector R&D in USA

Liquid Argon time projection chamber (LArTPC) is the candidate technology for the next generation large neutrino detectors. Unprecedented resolution and capability of particle ID (ionization energy loss, scintillation light) make it attractive for future high precision neutrino experiments. The necessary technologies were developed by the ICARUS collaboration in Italy and they are further studied in USA. In this talk, I would like to describe the overview of the LArTPC efforts in USA, with a special emphasis on the liquid argon scintillation light detection technology.

[slides]

05/12/2014 : Gary Royle (UCL)

Proton and Advanced Radiotherapy

Radiation therapy is a technology based clinical area which uses an array of photons and particles to target cancer sites. It has a number of areas in common with high energy physics. The talk will cover the basis of radiation therapy, the future technological needs, areas where high energy physicists can get involved from research to careers, and will highlight some clinical problems within the treatment of cancer patients that are relevant to the translation of high energy physics concepts and technology.

01/12/2014 : Jorge S Diaz (KIT)

Extra ordinary seminar: Testing Lorentz and CPT invariance with neutrinos (NEMO-3 and (Super)NEMO data)

Lorentz symmetry is a cornerstone of modern physics. As the spacetime symmetry of special relativity, Lorentz invariance is a basic component of the standard model of particle physics and general relativity, which to date constitute our most successful descriptions of nature. Deviations from exact symmetry would radically change our view of the universe and current experiments allow us to test the validity of this assumption. In this talk, I will describe how we can search for deviations from exact Lorentz and CPT invariance with neutrino oscillations, time-of-flight measurements, ultra-high-energy neutrinos, and double beta decay.

28/11/2014 : Prof. Philip Burrows (Oxford)

Precison Higgs Physics: The International Linear Collider Higgs Factory

An international team has recently completed the Technical Design Report for the International Linear Collider (ILC). The ILC is an electron-positron collider with a design target centre-of-mass energy of 500 GeV. Following the Higgs boson discovery it has been proposed to realise the ILC by building a 250 GeV ‘Higgs Factory’, and subsequently to upgrade it in stages to higher energies of 350 GeV, where it would also serve as a ‘top factory’, and eventually to 500 GeV to allow access to the top-Higgs and Higgs self- couplings. The Japanese particle physics community has proposed to host the collider in Japan. I will describe the programme of precision Higgs-boson measurements at the ILC. I will give an overview of the collider design, and report on the project status.

[slides]

21/11/2014 : Richard Savage (Warwick)

Using machine learning to cure cancer (!)

Medicine is undergoing a data revolution. From whole-genome sequencing to digital imaging and electronic health records, new sources of data are promising to revolutionise how we treat disease. With these opportunities, however, come significant challenges. The data are often high-dimensional, noisy, with complex underlying structure. And we may wish to combine multiple data types from very different sources. I'll give a tour of some of these issues, focusing on some of the projects we're working on to use statistical machine learning to get the most out of these data and hence improve, in particular, the treatment and curing of cancer.

14/11/2014 : Stuart Mangles (Imperial)

Laser wakefield accelerators : a laboratory source of femtosecond x-ray pulses

Laser wakefield accelerators are now capable of accelerating electron beams up to 1 GeV in just 1 centimetre of plasma. During the acceleration process the electron beam can oscillate, producing very bright femtosecond duration x-rays. In this talk I will introduce some of the key concepts of laser wakefield acceleration and x-ray generation. The x-rays we can generate have some highly useful properties including an ultra short (few femtosecond) duration, micrometer sized source and broad spectral coverage. I will discuss the use of this unique source of x-rays for applications such as probing matter under extreme conditions and medical imaging.

07/11/2014 : Cristina Lazzeroni (Birmingham)

Search for rare and forbidden Kaon decays at NA62

The NA62 Kaon programme will be reviewed. A selection of recent results on rare and Standard Model forbidden kaon decays will be presented, and the current status of the experiment and prospects for the measurement of the decay K+ to pi+ nu nubar will be summarised.

[slides]

31/10/2014 : Malcolm Fairbarn (Kings College)

Future Dark Matter searches and the Neutrino Background.

I will describe very simple models of dark matter and show how even with reasonable masses, effects such as resonances can lead to very small cross sections at direct detection experiments. I will then briefly discuss the usefulness in slightly more complicated simplified models than the effective operator approach. I will then present some work constraining such models using dijet studies at the LHC and indirect detection and show how direct detection cross sections can be very small in such scenarios, even with good relic abundance. Small cross sections run the risk of being potentially undetectable due to the neutrino background, even with very large future direct detection experiments. I will spend the rest of my talk explaining future strategies for getting the dark matter signal out of the neutrino background.

17/10/2014: Aurélien Benoit-Lévy (UCL)

Inflation, B-modes and dust: Planck's view on BICEP2 results.

The Planck collaboration has recently published new results on the characterisation of polarised dust emission at intermediate and high Galactic latitudes. Although these results specifically focus on the properties of Galactic dust, they are relevant for cosmological studies. Indeed dust is a known contaminant of the long sought-after primordial B modes from Inflation. In this talk, I will focus on how these new results from Planck impact the interpretation of the recent claims from the BICEP2 collaboration.

[slides]

24/09/2014 : 13:00-17:00 : HEP Group Day (E3/E7)

23/09/2014 : 10:30 - 16:00 : 1st Year PhD Talks (E3/E7)

11/09/2014 : Richard Ruiz (University of Pittsburgh)

State-of-the-Art Tests of Lepton Number Violation and Seesaw Mechanisms at Hadron Colliders

TBA

[slides]

13/06/2014 : Prof. Ulrik Egede (Imperial)

Search for HIdden Particles (SHIP) at the SPS

Particles physics faces the contradiction of a Standard Model, that seems perfect and can exist without corrections to the Planck scale, and the inability of the same Standard Model to explain dark matter, neutrino masses and baryogenesis. I will give a brief overview of the vMSM, a minimal extension to the Standard Model that may solve this contradiction. The vMSM predicts the existence of new GeV mass neutral leptons and I will present how a fixed target experiment located at a new beamline of the SPS is ideal to search for these. Possibilities for involvement of UK groups will be discussed.

[slides]

27/05/2014 : Jouni Suhonen (University of Jyväskylä) - 2pm-3pm

Rare Weak Decays and Nuclear Structure

I will discuss different types of rare decays. I divide these decays in three categories: A. Decays with (ultra) low Q values; B. Decays between states with large differences in the initial and final angular momenta; C. Weak-interaction processes of higher order. The A category contains potential candidates for neutrino-mass measurements in beta decays. Category B highlights cases where single and double beta decays compete. Category C highlights the large variety of different double beta decays that are possible via exchange of a light Majorana neutrino. In particular, the less discussed positron-emission modes of double beta decays, including the interesting resonant neutrinoless double electron capture mode, are elucidated.

27/05/2014 : Mikhail Shaposhnikov (EPFL) - 4pm-5pm

Higgs inflation at the critical point

Higgs inflation can occur if the Standard Model is a self-consistent effective field theory up to inflationary scale. This leads to a lower bound on the Higgs boson mass, M_h > M_crit. If M_h is more than a few hundreds of MeV above the critical value, the Higgs inflation predicts the universal values of inflationary indexes, r= 0.003 and n_s= 0.97, independently on the Standard Model parameters. We show that in the vicinity of the critical point M_crit the inflationary indexes acquire an essential dependence on the mass of the top quark m_t and M_h, and can be consistent with BICEP 2 data.

16/5/2014, Phillipe Mermod (Geneva)

"Magnetic monopoles at the LHC and in the Cosmos"

Dirac showed in 1931 that the existence of one magnetic monopole in the Universe would explain why electric charge is quantised. The monopole also arises as a natural consequence of Grand Unification theories. While collider experiments provide direct laboratory studies, stable particles with masses beyond the reach of man-made accelerators could have been produced in the early Universe and still be present today. I shall review experimental searches for monopoles at colliders, focusing on recent developments at the LHC. I shall also provide a survey of monopole searches with cosmic-ray detectors and trapped in matter, and propose a few promising avenues for the future.

09/05/2014 : Moritz McGarrie (University of the Witwatersrand)

SUSY model building for a 126 GeV Higgs

his talk will review the current status of minimal models of supersymmetry breaking and explore two possible models which can achieve the correct Higgs mass and still allow for sparticles accessible to the LHC's reach. In the first example we use the HEP tool SARAH to build two tailor made spectrum generators to analyse a Higgs extension (non decoupled D-terms) of the MSSM. We then explore the LHC & ILC's capability to determine their effect through their enhancement of Higgs branching ratios with respect to the Standard Model. In the second model, we explore flavour-gauge mediation to obtain light 3rd generation squarks, whilst keeping the 1st and 2nd generation above exclusions. In particular this model can also generate non-degenerate 1st and 2nd generation squarks and, although in the framework of gauge mediation, leads to mild flavour changing neutral currents at, below and above current limits.

04/04/2014 : Dimitris Varouchas(LPNHE-Paris)

H -> tautau in ATLAS

In this seminar, a search for the Standard Model (SM) Higgs boson with a mass of 125 GeV decaying into a pair of tau leptons will be reported. The analysis is based on data samples of p-p collisions collected by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 20.3.0 1/fb at centre-of-mass energy of sqrt(s)=8 TeV. The observed (expected) deviation from the background-only hypothesis corresponds to a significance of 4.1 (3.2) standard deviations, and the measured signal strength is μ = 1.4+0.5 −0.4. This is evidence for the existence of H → τ+τ− decays, consistent with the Standard Model expectation for a Higgs boson with mH = 125 GeV. A brief comparison with the respective CMS result will be also presented.

28/03/2014 : MOVED to 31/03/2014 ! UCL third year students

MOVED! UCL third year student IOP practise talks!

The UCL third year student IOP practise talks will now be on Monday 31/03/2014!

21/03/2014 : Prof. Tegid Jones (UCL)

Forty years since the Neutral Current (Z0) Discovery in Gargamelle. The UCL Contribution.

The discovery of neutral currents (1973/74) was the first confirmation of the SU(2)xU(1) electro-weak unified theory. UCL HEP was part of the Gargamelle collaboration which made the first truly significant discovery at CERN. Forty years later the UCL-HEP group contributed to the discovery of the Higgs Boson, thereby completing the understanding of symmetry breaking in the SU(2)xU(1) model.

14/03/2014 : Ian P. Shipsey (Oxford)

The Large Synoptic Survey Telescope (for particle physicists)

Recent technological advances have made it possible to carry out deep optical surveys of a large fraction of the visible sky. These surveys enable a diverse array of astronomical and fundamental physics investigations including: the search for small moving objects in the solar system, studies of the assembly history of the Milky Way, the exploration of transient sky, and the establishment of tight constraints on models of dark energy using a variety of independent techniques. The Large Synoptic Survey Telescope (LSST) brings together astrophysicists, particle physicists and computer scientists in the most ambitious project of this kind that has yet been proposed. With an 8.4 m primary mirror, and a 3.2 Gigapixel, 10 square degree CCD camera, LSST will provide nearly an order of magnitude improvement in survey speed over all existing optical surveys, or those which are currently in development. Expected to begin construction later in 2014, and to enter commissioning in 2020, in its first month of operation LSST will survey more of the universe than all previous telescopes built by mankind. Over the full ten years of operation, it will survey half of the sky in six optical colors down to 27th magnitude. Four billion new galaxies and 10 million supernovae will be discovered. At least 800 distinct images will be acquired of every field, enabling a plethora of statistical investigations for intrinsic variability and for control of systematic uncertainties in deep imaging studies. LSST will produce 15 terabytes of data per night, yielding a data set of over 100 petabytes over ten years. Dedicated Computing Facilities will process the image data in near real time, and issue worldwide alerts within 60 seconds for objects that change in position or brightness. In this talk some of the science that will be made possible by the construction of LSST, especially dark energy science, which constitutes a profound challenge to particle physics and cosmology, and an overview of the technical design and current status of the project will be given.

[slides]

28/02/2014 : Jo van den Brand (NIKHEF)

Probing dynamical spacetimes

Albert Einstein's theory of general relativity, published in 1915, gave science a radically new way of understanding how space, time and gravity are related. Gravity is defined as the curvature of spacetime and is caused by the four-momentum of matter and radiation. Einstein predicted that accelerating objects will cause vibrations in the fabric of spacetime itself, so-called gravitational waves. The detection of gravitational waves is the most important single discovery to be made in the physics of gravity. Gravitational waves exist in any theory of gravity that incorporates a dynamical gravitational field, be it a metric theory such as general relativity (or one of its generalizations), or a non-metric theory such as string theory. Observations of binary pulsars, whose orbital motion evolves in agreement with general relativity, revealed that gravitational radiation must exist. However, no direct observation of gravitational waves has been reported to date. Discovering gravitational waves would confirm once and for all that gravity is a fundamental dynamical phenomenon. The Virgo detector for gravitational waves consists mainly of a Michelson laser interferometer made of two orthogonal arms being each 3 kilometres long. Virgo is located within the site of EGO, European Gravitational Observatory, based at Cascina, near Pisa on the river Arno plain. Virgo scientists, in collaboration with LIGO in the USA and GEO in Germany, have developed advanced techniques in the field of high power ultra-stable lasers, high reflectivity mirrors, seismic isolation and position and alignment control. In 2015 these collaborations with turn on their advanced instruments in their quest for first detection of gravitational wave events.

26/02/2014 : George Efstathiou (Cambridge)

SPREADBURY LECTURE (JZ Young LT) : The Birth Of The Universe

Modern physics attempts to explain the full complexity of the physical world in terms of three principles: gravity, relativity and quantum mechanics. This raises important fundamental questions such as why is our Universe so large and old? Why is it almost, but not perfectly, homogeneous and isotropic? I will describe how recent measurements of the cosmic microwave background radiation made with the Planck Satellite can be used to answer these questions and to elucidate what happened within 10-35 seconds of the creation of our Universe.

21/02/2014 : Nikos Konstantinidis (UCL)

The High Luminosity LHC programme

As the LHC machine and experiments are preparing frantically to start data taking at design energy and luminosity (and slightly above), an equally intense and exciting programme of R&D and physics studies is ongoing for the High Luminosity (HL-) LHC project, proposed to start in about 10 years, that would deliver 3000/fb to each general purpose detector by the mid-2030s. I will discuss the science case for HL-LHC, the challenges for the accelerator and the experiments, and the ongoing R&D, particularly on the tracking and triggering systems of the experiments

[slides]

14/02/2014 : Werner Vogelsang (UNI Tuebingen)

QCD resummation for jet and hadron production

Cross sections for the production of jets or identified hadrons in pp collisions play an important role in particle physics. At colliders, jets are involved in many reactions sensitive to new physics and their backgrounds. In lower-energy collisions, produced hadrons probe the inner structure of the nucleon and the fragmentation process. Both observables have in common that their use crucially relies on our ability to do precision computations of the underlying hard-scattering reactions in QCD perturbation theory. In this talk, we discuss the role of higher-order QCD corrections to these reactions. Specifically, we address the resummation of large logarithmic "threshold" corrections to the relevant partonic cross sections. Among other things, this allows us to determine dominant next-to-next-to-leading order QCD corrections to jet production at the LHC and Tevatron. Detailed phenomenological studies are presented.

[slides]

07/02/2014 : Paschal Coyle (In2p3, France)

Neutrinos out of the blue

The road to neutrino astronomy has been long and hard. The recent observation of a diffuse flux of cosmic neutrinos by IceCube heralds just the start of this new astronomy. In this seminar a brief outline of the various experimental efforts worldwide to detect cosmic neutrinos are described and a selection of the physics results presented. Particular emphasis is given to ANTARES, a neutrino telescope located in the deep sea 40km off the southern coast of France. The European neutrino astronomy community has recently started the construction of KM3NeT, a several cubic kilometre neutrino telescope in the Mediterranean Sea. The plans of this new research infrastructure are described. Finally, the potential for a measurement of the neutrino mass hierarchy, with a densely instrumented detector configuration in ice (PINGU) and water (ORCA) is discussed.

[slides]

31/01/2014 : Alexander Mitov (Cambridge)

Recent developments in top physics at hadron colliders

I will review the available NNLO results for top pair production at hadron colliders and will demonstrate their effect on various analyses of SM and bSM physics. I will then discuss the prospects for further NNLO level calculations in top physics and how they may influence existing results and open problems in top physics and beyond.

[slides]

24/01/2014 : Jennifer Smillie (University of Edinburgh)

Jets, Jets, Higgs & Jets

The LHC is pushing the limits of our theoretical descriptions, especially in multi-jet processes. I will discuss the challenges posed by the large higher-order perturbative corrections, and describe the High Energy Jets framework which provides an alternative all-order description encoding the dominant pieces of the hard-scattering matrix elements. I will illustrate the effectiveness of this method with comparisons to LHC data, and what it teaches us about QCD at the LHC. In the last part of the talk, I will discuss the importance of this in the light of Higgs+dijets studies with an emphasis on vector boson fusion (VBF) channels and will discuss the implications of the previous results. I will show some results from ongoing work to describe the impact of VBF cuts on the gluon-gluon fusion contribution.

[slides]

13/12/2013 : Lea Reichhart (UCL)

First results from the LUX Dark Matter Experiment

A vast number of astronomical observation point towards the existence of an unknown dark component dominating the matter content of our Universe. The most compelling candidates for dark matter are the Weakly Interacting Massive Particles (WIMPs), which have great potential to be detected in deep underground low background experiments, looking for direct interactions of WIMPs with dedicated target materials. Very recently, the Large Underground Xenon (LUX) experiment, operated in the Davis Cavern of the SURF laboratory, USA, has announced results from its first science run. From an exposure of 85 days, having found no evidence of signal above expected background, LUX has set constraints on scalar WIMP-nucleon interactions above 7.6x10-46 cm2 at 33 GeV/c2 WIMP mass (90% C.L.) - three times more sensitive than any competing experiment. This first result also seriously challenges the interpretation of hints of signal detected in other experiments as arising from low-mass WIMPs.

06/12/2013 : Bryan Lynn (UCL/CERN)

Chiral Symmetry Restoration, Naturalness and the Absence of Higgs-Mass Fine-Tuning 1: Global Theories

The Standard Model (SM), and the scalar sector of its zero-gauge-coupling limit -- the chiral-symmetric limit of the Gell Mann-Levy Model (GML) -- have been shown not to suffer from a Higgs Fine-Tuning (FT) problem due to ultraviolet quadratic divergences (UVQD). In GML all UVQD are absorbed into the mass-squared of pseudo Nambu-Goldstone (pNGB) bosons. Since chiral SU(2)_{L-R} symmetry is restored as the pNGB mass-squared or as the Higgs vacuum expectation value (VEV) are taken to zero, small values of these quantities and of the Higgs mass are natural, and therefore not Fine-Tuned. Our results on the absence of FT also apply to a wide class of high-mass-scale (M_{Heavy}>>m_{Higgs}) extensions to a simplified SO(2) version of GML. We explicitly demonstrate naturalness and no-FT for two examples of heavy physics, both SO(2) singlets: a heavy (M_S >> m_{Higgs}) real scalar field (with or without a VEV); and a right-handed Type 1 See-Saw Majorana neutrino with M_R >> m_{Higgs}. We prove that for |q^2| << M_{Heavy}^2, the heavy degrees of freedom contribute only irrelevant and marginal operators. The crucial common property of such high-mass-scale extensions is that they respect chiral SO(2)_{L-R} symmetry. GML is therefore natural and not FT, not just as a stand-alone renormalizable field theory, but also as a low energy effective theory with certain high-mass-scale extensions. Phenomenological consequences include the renewed possibility of thermal lepto-genesis, and subsequent baryon-number asymmetry, in the neutrino-MSM. We conjecture that, since gravity couples democratically to particles, certain quantum gravitational theories that respect chiral symmetry will also retain low-energy naturalness, and avoid FT problems for GML (and maybe the SM). Absent a SM FT problem, there should be no expectation that LHC will discover physics beyond the SM which is unrelated to neutrino mixing, the only known experimental failure of the SM.

29/11/2013 : Matt Lilley (Imperial)

Feeling the Fusion Burn

The age of fusion energy is almost upon us, creating and sustaining hot plasmas of 150 million degrees is now a routine operation performed all around the world. We are ready for next big challenge - the burning plasma - in which the fusion reactions are self sustaining. This is a highly non thermal system which is prone to instability. The nonlinear character of the instability determines the fate of the plasma, either ignition or a mere fizzle. In this presentation we will explore the physical processes behind these burning plasma instabilities and discus the challenges that lie ahead.

[slides]

CANCELED!: 22/11/2013 : Nikos Konstantinidis (UCL)

The High Luminosity LHC programme

As the LHC machine and experiments are preparing frantically to start data taking at design energy and luminosity (and slightly above), an equally intense and exciting programme of R&D and physics studies is ongoing for the High Luminosity (HL-) LHC project, proposed to start in about 10 years, that would deliver 3000/fb to each general purpose detector by the mid-2030s. I will discuss the science case for HL-LHC, the challenges for the accelerator and the experiments, and the ongoing R&D, particularly on the tracking and triggering systems of the experiments

08/11/2013 : Gabriel Facini (CERN)

H -> bb in ATLAS

Since the discovery of a Higgs-­like boson by the ATLAS and CMS experiments at the LHC, the emphasis has shifted towards measurements of its properties and the search in more challenging channels in order to determine whether the new particle is the Standard Model (SM) Higgs boson. Of particular importance is the direct observation of the coupling of the Higgs boson to fermions. A comprehensive review of the latest ATLAS result in the search for the Higgs boson decaying to a b-­quark pair int associated production channel will be given.

25/10/2013 : Lauren Tompkins (University of Chicago)

FTK: A hardware-based track finder for the ATLAS trigger

The spectacular performance of the LHC machine challenged the ATLAS and CMS detectors to contend with an average of 25 proton-proton interactions per beam crossing in 2012. Projections for 14 TeV running in 2015 and beyond suggest that the detectors should prepare for up to 80 interactions per crossing. In these dense environments, identifying the physics objects of interest, such as isolated leptons, taus and b-jets is of paramount importance for a successful physics program. The ATLAS experiment is developing a hardware based track finder, FTK, which will perform full silicon detector tracking within 100 microseconds of a Level 1 trigger accept at luminosities of 3x10^34 cm^-2 s^-1, significantly improving the track-based isolation, secondary vertex tagging and track-based tau finding done at Level 2. I will discuss the FTK design and performance prospects, as well as report on successful prototype tests completed thus far.

[slides]

11/10/2013 : Bhupal Dev, University of Manchester

Heavy Neutrino Searches at the LHC

One of the simplest extensions of the Standard Model to explain the non-zero neutrino masses is to introduce heavy neutrinos. In this talk, we will review the existing experimental constraints on the masses and mixing of these heavy neutrinos. We will then discuss their ongoing searches at the LHC and some recent efforts to improve their sensitivity.

[slides]

24/09/2013 : 1st Year Student PhD Talks : 13:00 - 18:00

B05 Lecture Theatre in the Chadwick Building.

23/09/2013 : Group Day : 13:00 - 17:00 + drinks (E1)

B17 (Basement) 1-19 Torrington Place.

18/09/2013 : 2nd Year Student PhD Talks : 10:00 - 17:00

E3/E7 Physics and Astronomy Department.

04/07/2013 : Prof. Jose Valle, (IFIC/CSIC - U. Valencia)

Neutrinos and Dark Matter

I will review the status of neutrino mass and mixing parameters, theoretical modeling and cosmological implications. In particular I discuss how neutrino mass and dark matter may be closely connected and indicate possible direct, indirect and collider detection prospects.

28/06/2013 : Brian Rebel, Fermilab

Liquid Argon Detectors at Fermilab: From R&D to LBNE

Liquid argon time projection chambers (LArTPCs) are an exciting new technology for neutrino detectors. This technology provides excellent position resolution that rivals bubble chamber images, but in a digital format. The striking advantage of liquid argon time projection chambers for neutrino physics is the ability to distinguish between electrons, produced in charged current interactions, and gammas, produced by the decay of neutral pions created in neutral current interactions, with high efficiency. This talk will outline the Fermilab R&D program aimed toward development of the multi-kiloton LBNE detector for long baseline neutrino physics. Results from the various aspects of the program will be presented, as well as the status of LBNE.

29/05/2013 : Alexander Grohsjean, DESY

A quark comes of age: latest highlights in top quark physics.

The discovery of the top quark in 1995 at the Fermilab Tevatron collider was a remarkable confirmation of the standard model of particle physics. Its short lifetime provides the possibility to probe the properties of a bare quark With increasingly large integrated luminosities, the characteristics of this particle, as well as its production and decay properties have been measured with ever greater precision. The analysis of top-quark events triggered the development of new analysis tools and offered an excellent starting point for searches of new phenomena. In this summary, following a short historic perspective, I present recent measurements from the D0 experiment, as well as new ATLAS results from the LHC at 7 and 8 TeV.

17/05/2013 : Jonathan Hays, Queen Mary

LHC Higgs results

Last year the ATLAS and CMS experiments announced the discovery of a new particle with a mass of around 126 GeV and a strong candidate for being a Higgs boson. Measurements with the full 2011+2012 dataset have further confirmed this. The latest results in experimental Higgs physics are presented from both experiments, concentrating on the new particle. This includes the continuing search for signals in those modes yet to find evidence for the new particle, property measurements in the diboson modes, and a variety of global fits to data across different channels to investigate compatibility with the Standard Model. Additionally, the compatibility of the results across experiments will be briefly discussed along with some thoughts on the outlook for the Higgs programme at the LHC.

[slides]

10/05/2013 : Dr Will Thomas, Centre for the History of Science, Technology and Medicine, Imperial College

Problems in Particle Detection 1930-1950: New Ways to Talk about the History of Physics

Early developments in particle physics were based on the analysis of cosmic rays and radioactive materials before these sources were supplanted by high-energy accelerators circa 1950. Commonly used particle detection technologies included cloud chambers, arrays of coincidence counters, and, after 1945, nuclear emulsions. These technologies all yielded fairly imprecise information about the particles passing through them, necessitating experimenters to deploy strategies to arrive at what they viewed as legitimate interpretations of events. These strategies included using inference to establish what sorts of particles were being detected, the aggregation of evidence, and an increasingly intensive use of nuclear physics knowledge to narrow a range of possible interpretations. It will be suggested that articulating the nature of these strategies, and paying attention to how experimenters deployed them, allows for a good way of discussing historical experimenters’ skill, certainly over and above a simple cataloguing of their discoveries.

[slides]

03/05/2013 : Gino Isidori, INFN, Frascati National Laboratories

Standard Model and beyond after the the Higgs discovery

We discuss the implications of the recent Higgs discovery, and particularly of the Higgs mass measurement, for the stability of Higgs potential and, more generally, for the completion of the Standard Model at high energies.

[slides]

15/03/2013 : Dr. Bela Majorovits, Max-Planck-Institut für Physik

Understanding Neutrinos?GERDA and the Neutrinoless Double Beta-Decay

Observation of neutrinoless double beta (0vbb) -decay could answer the question whether Neutrinos are their own anti-particles or not and could yield information on the absolute mass scale of neutrinos. The most stringent half-life limit for 76Ge is T1/2>1.9 1025 years. This can be translated to the lowest present limit for the effective Majorana neutrino mass of < 0.3eV. Part of the Heidelberg-Moscow collaboration claims to have observed 0vbb-decay in 76Ge with T1/2=1.2 1025 years, however this result is controversial. A short motivation for 0vbb-decay searches will be given. The principle of 0vbb-searches utilizing High Purity Germanium enriched in the isotope 76Ge detectors will be introduced. The general design features of the GERDA experiment - designed to confirm or refute the claim within one year of measurement will be shown. Results from the GERDA commissioning runs and the status of GERDA data taking with enriched detectors will be discussed. Plans and status of preparations of the second phase of the GERDA experiment will be shown.

[slides]

08/03/2013 : Mat Charles, Oxford

Charm results from LHCb

Highlights from LHCb's charm physics programme are presented, including searches for the highly suppressed decays D+ -> pi+ mu- mu+, D+ -> pi- mu+ mu+, and D0 -> mu- mu+; a measurement of meson mixing in D0 -> K+ pi-; and a search for CP violation in two-body D0 decays.

[slides]

01/03/2013 : Prof. Chris Mabey, Middlesex Business School

Big Lessons from Big Science

The ATLAS collaboration comprises 3000 physicists from 140 Institutes in 37 countries collaborating on a ‘big science’ project based at CERN near Geneva. As a loosely-coupled, global network of knowledge activists working at the forefront of science, it is prototypical of many knowledge-intensive agencies and firms. What can be learnt from this unusual collaboration about the way tacit knowledge is surfaced and exchanged across professional, cultural and geographic boundaries? ATLAS is feted as a remarkably democratic and highly productive partnership. How does it achieve this and what are the lessons for the effective leadership of knowledge? Chris will share insights from his recent ESRC-funded project (2009-12).

[slides]

15/02/2013 : Prof. Robert Thorne, UCL

Parton Distribution Functions at the LHC

I discuss the current status of parton distributions, compare to LHC data and present the range of predictions for LHC processes. Some significant discrepancies are found between different PDF sets, particularly regarding predictions for Higgs boson cross sections and the asymmetry between W^+ and W^- production. I examine possible causes for this, concentrating on issues of parameterisation dependence and the treatment of heavy flavours in the fits.

[slides]

08/02/20153 : Dr. Bobby Acharya, Kings College London

Generic Predictions from string/M theory for Particle Physics and Dark Matter

[slides]

01/02/2013 : Dr. Ricardo Silva, Department of Statistical Science, UCL

The Structure of the Unobserved

Hidden variables are important components in many multivariate models, as they explain dependencies among recorded variables and may provide a compressed representation of the data. In this talk, I will provide some overview of my line of work on how latent structure can be exploited in machine learning and computational statistics applications. In particular, we will go through the following topics: 1. How to measurement error problems have a causal interpretation and what can potentially be done to identify probabilistic and causal relations among variables that cannot be recorded without error 2. How dependencies among interacting individuals in a network can be explained by hidden common causes and what their roles are in prediction problems 3. How measurements can be compressed into fewer items without losing relevant information from the data, as postulated from a latent variable model, with applications in social sciences

[slides]

25/01/2013 : Prof. Buzz Baum, LMCB, UCL

A noisy path to order: refinement of a developing tissue

In my talk I will discuss the process of tissue refinement, whereby an ordered epithelial is generated from an initially disordered state through noisy processes that cause cells to compete for space and fate.

[slides]

28/06/2013 : Jennifer Smillie, (University of Edinburgh)

TBA

TBA

18/01/2013 : Dr. Maurizio Piai, Swansea

Holographic techni-dilaton

I review the status of theoretical and phenomenological studies on the holographic techni-dilaton, a light composite scalar present in the spectrum of a class of strongly-coupled models of electroweak symmetry breaking. The experimental signatures of such scalar are similar to those of the Higgs particle of the minimal version of the Standard Model, with important observable differences is some of the search channels. The 125-126 GeV scalar discovered by ATLAS and CMS could be such particle, and I will discuss how to test this hypothesis in future theoretical as well as experimental studies.

[slides]

11/01/2013 : Prof. Jon Butterworth, UCL

Standard Model physics

I'll review a selection of LHC measurements of jets, photons and weak bosons, show comparisons to Standard Model predictions, and discuss some lessons learned and future prospects.

[slides]

14/12/2012 : Prof. Jeff Forshaw, Manchester

The breakdown of collinear factorization in QCD

Collinear factorization underpins the calculation of many particle physics cross sections, through the use of parton distribution and fragmentation functions. All of the principal Monte Carlo event generators exploit it in their design. In this talk I will explain that in general the factorization does not hold in hadron-hadron collisions and shed light on the mechanism of the breakdown in the language of perturbation theory.

[slides]

07/12/2012 : Dr. Stephen West, RHUL

Models of Dark Matter

I will outline some alternatives to the standard neutralino dark matter scenario. In particular, I will review asymmetric dark matter and the production of dark matter via ``freeze-in". I will present the possible ways in which we can search for these candidates in dedicated dark matter search experiments and at colliders.

30/11/2012 : Dr. Chamkaur Ghag, UCL

Direct Dark Matter detection

Discovery of the nature of dark matter is internationally recognized as one of the greatest contemporary challenges in science, fundamental to our understanding of the Universe. The most compelling candidates for dark matter are Weakly Interacting Massive Particles (WIMPs) that arise naturally in several models of physics beyond the Standard Model. Although no definitive signal has yet been discovered, the worldwide race towards direct detection has been dramatically accelerated by the progress and evolution of liquid xenon (LXe) time projection chambers (TPCs). The XENON phased programme operates LXeTPCs at Gran Sasso, Italy, and has released results from analysis of 225 days of WIMP search data from the XENON100 detector - presently the most sensitive instrument in the worldwide hunt for WIMPs. XENON100 finds no evidence of signal above expected background and constrains scalar WIMP-nucleon interactions above 2x10-45 cm2 at 55 GeV/c2 WIMP mass (90% C.L.) - over an order of magnitude more stringent than any competing experiment. This result seriously challenges interpretation of the DAMA, CoGeNT or CRESST-II observations as being due to scalar WIMP-nucleon interactions.

[slides]

23/11/2012 : Prof. David Evans, Birmingham

Probing the Quark-Gluon Plasma - recent results from ALICE at the LHC

ALICE is a general purpose heavy-ion experiment aimed at studying QCD at extreme energy densities and the properties of the deconfined state of matter, known as a quark-gluon plasma. A selection of the latest results will be presents, together with the first results from proton-lead collisions.

[slides]

26/10/2012 : Dr. Simon Jolly

Proton Accelerators for Cancer Therapy

Proton beam therapy (PBT) is a more sophisticated form of radiotherapy for the treatment of cancer. Due to the Bragg Peak, protons can deliver the necessary dose to the tumour site much more precisely than the 6-18 MeV photons used in conventional radiotherapy. This is particularly valuable for tumours in the head and neck and central nervous system and for treating children, whose growing organs need to be protected from excessive dose. Until now proton therapy was only available from the Clatterbridge Centre for Oncology on the Wirral, and then only for eye treatments using 62 MeV protons. Two new sites are planned for the UK to deliver large-scale proton therapy treatment for the first time: at the Christie Hospital in Manchester and at UCL Hospital. I will describe the reasons for using protons over photons and the accelerator technologies used to deliver 70-250 MeV protons for the full range of treatment we will offer at UCLH. I will also cover some of the issues in selecting the right accelerator technology in my role as the accelerator lead for the new UCLH PBT facility and as an advisor to the Christie programme.

[slides]

19/10/2012 : Prof. Kael Hanson, Brussels

Particle astrophysics at 90° south : reports from the IceCube Neutrino Observatory

The IceCube Neutrino Observatory is a kilometer-scale cosmic ray muon and neutrino telescope deployed in the deep ice at the South Pole. It detects the Cherenkov radiation emitted by charged particles in transit through the transparent glacial medium by means of a huge array of photomultiplier tubes, each of which independently registers the intensity and arrival time of the radiated photons. The resulting ensemble of hits is processed by event reconstruction algorithms which determine the energy, direction, and type of particle underlying the event. Under construction since 2003, the so-called IC86 array was finally completed December 2010 with the installation of the 86th deep ice string and the full detector was commissioned and placed in operation in May 2011. This talk outlines the science goals of the facility and highlights the results to date that have been released by the IceCube collaboration: searches for high-energy and ultrahigh-energy cosmic neutrinos and lower-energy neutrinos from dark matter; measurements of the cosmic ray anisotropy; detection of neutrino oscillations at high energies. Planned extensions to IceCube are additionally described. Finally, the Askaryan Radio Array (ARA) is introduced. It is an array of radio antennas located next to the current IceCube array which is expected to eventually cover an area of over 100 square kilometers and which targets the detection of the GZK neutrino flux at extreme high-energies which should result from the observed absorption of cosmic rays at these energies.

[slides]

12/10/2012 : Dr. Tamsin Edwards, Bristol

Predicting future changes in climate and sea level

How can we predict the future of our planet? I will give an overview of modelling and assessment of uncertainty for future climate change and sea level, focusing on the world-leading UK Climate Projections 2009 and our recent research on Antarctica.

[slides]

05/10/2012 : Dr. Kumiko Kotera

From the magnetized Universe to neutrinos: a life of an ultrahigh energy cosmic ray

The origin of ultrahigh energy cosmic rays (UHECRs, particles arriving on the Earth with energy 10^17- 10^21 eV) is still a mystery. I will review the experimental and theoretical efforts that are being deployed by the community to solve this long-standing enigma, including the recent results from the Auger Observatory. I will describe in particular the interactions experienced by UHECRs while propagating from their sources to us, in the cosmic magnetic fields and the various intergalactic backgrounds. These interactions, that induce deflections and multi-messenger production (neutrinos, gamma-rays and gravitational waves) could reveal crucial information about the path taken by these particles, and help us track down their progenitors. I will also focus on one candidate source that has been little discussed in the literature: young rotation-powered pulsars. The production of UHECRs in these objects could give a picture that is surprisingly consistent with the latest data measured with the Auger Observatory.

[slides]

29/06/2012 : Prof. Mark Lancaster & Dr. Dave Waters

History of the Tevatron & The Mass of the W Boson

CDF, with significant involvement of the UCL group, have published a W mass measurement with greater precision that all previous measurements combined. We'll take a look at the history of the Tevatron project and particularly the latest ground-breaking W mass measurement. This is an important legacy of the Tevatron as all eyes are now focused on the LHC ...

[slides(Dave),slides(Mark)]

14/06/2012 : Prof. Kam-Biu Luk, University of California at Berkeley and Lawrence Berkeley National Laboratory

Latest results of the Daya Bay Reactor Antineutrino Experiment

The goal of the Daya Bay Reactor Antineutrino Experiment is to determine the neutrino-mixing angle, &theta13, with a precision better than 0.01 in sin2(&theta13). The value of sin2(&theta13) is measured by comparing the observed electron-antineutrino rates and energy spectra with functionally identical detectors located at various baselines from the reactors. This kind of relative measurement using a near-far configuration significantly reduces the systematic errors. Daya Bay began data taking near the end of 2011 and reported the observation of a non-zero value for &theta13 recently. In this seminar, an overview of the experiment and the latest results from Daya Bay will be presented.

[ slides]

01/06/2012 : Basil Hiley, Birkbeck College and Rob Flack, UCL

Weak measurement: a new type of quantum measurement and its experimental implications

We will discuss the notion of a ‘weak measurement’, originally introduced by Aharonov et al and carefully analyzed by Duck et al. This technique opens up new experimental possibilities for exploring quantum phenomena. It has already been used to measure the spin Hall effect of light and to measure photon ‘trajectories’ in a two slit interference set up, traditionally deemed to be impossible without destroying the interference effects. We will discuss the theoretical basis for the experimental technique and propose new experiments to explore foundational issues, throwing new light on the Bohm interpretation.

[slides-1, slides-2]

18/05/2012 : Dr. Frank Deppisch, UCL

Lepton Flavour and Number Violation in Left-Right Symmetrical Models

We discuss lepton flavour and number violating processes induced in the production and decay of heavy right-handed neutrinos at the Large Hadron Collider. Such particles appear in Left-Right symmetrical extensions of the Standard Model as the "messengers"' of neutrino mass and may have masses of order TeV, potentially accessible at the LHC. We determine the expected sensitivity on the right-handed neutrino mixing matrix, as well as on the right-handed gauge boson and heavy neutrino masses, and compare the results with low-energy probes such as searches for mu-e conversion in nuclei and neutrinoless double beta decay.

[ slides]

11/05/2012 : Prof. Max Klein, Liverpool

The LHeC Project at CERN

An overview is given on the physics, detector and accelerator designs of the Large Hadron electron Collider. The LHeC is a new electron- proton/ion collider, which, operating at TeV energy and using the intense LHC p/A beams, is designed to open a new chapter of deep inelastic lepton-hadron physics.

[slides]

04/05/2012 : Dr. Marumi Kado, LAL

Higgs searches at the LHC

This talk will give an overview of the searches for the Higgs boson with the ATLAS and CMS detectors at the LHC with the full 2011 dataset, corresponding to an integrated luminosity of nearly 5 fb-1. Both experiments have explored the Higgs boson mass hypotheses range from 110 GeV up to 600 GeV. Most of this range is now excluded at a high confidence level. However, at its low end, for Higgs boson mass hypotheses close to 125 GeV, both experiments observe an excess of events above the background expectation. More data are required to determine the origin of this excess. These results will be reviewed and the short to medium term prospects will be briefly discussed.

[slides]

27/04/2012 : Dr. Tracey Berry, Royal Holloway

Searching for Extra Dimensions at ATLAS

The ATLAS experiment at the LHC has been recording data from proton-proton collisions at a centre-of-mass energy of 7 TeV since March 2010. In 2011 it collected an integrated luminosity of over 5 inverse femtobarns. The combination of the large amount of data available and the excellent detector performance has enabled searches for evidence of new physics at this unprecedented energy scale to be performed. In this talk I will give an overview of the ATLAS searches for extra dimensions.

[slides]

20/04/2012 : Prof. Mark Lancaster, UCL

The Muon: a probe for new physics

The muon whose discovery in 1937 caused a furore at the time is about to have a renaissance. The availability of new high intensity proton sources at PSI, J-PARC and FNAL will allow the muon's decay modes and dipole moments to be probed to an unprecedented precision. Lepton violation measurements can probe physics far beyond the LHC energy scale and elucidate and resolve degeneracy in new physics models potentially exposed by the LHC. In conjunction with measurements of neutrinoless double beta decay and neutrino oscillations, the muon measurements can also shed light on the mechanism that has generated the universe's matter anti-matter asymmetry. In this talk I will discuss the motivation for, and describe, the next generation of muon experiments and particularly the UK involvement in the COMET experiment.

[slides]

23/03/2012 : Dr. Aidan Robson, Glasgow

Final Higgs results from the Tevatron

I will present Higgs search results from the complete Tevatron dataset, which were shown for the first time two weeks ago, and discuss them in the context of recent LHC results.

[slides]

09/03/2012 : Dr. Dan Browne, UCL

Putting Bell inequality violation to work

Entanglement and the violation of Bell inequalities are the most striking examples of the incompatibility of quantum physics and the classical world. Quantum experiments can exhibit correlations which would be impossible in any classical world, unless information could travel faster than light. This behaviour is captured by Bell inequalities and other effects. Giving a general introduction to these effects for the non-specialist, I will give examples of the non-classical correlations which can lead to Bell inequality violations and describe how, in my own recent research, Bell inequality violation has been shown to represent something useful - computation.

[slides]

02/03/2012 : Dr. Boris Kayser, Fermilab

Neutrino Phenomenology, News, and Questions

We will explain the quantum mechanics of neutrino oscillation, which is a quintessentially quantum mechanical phenomenon. Then we will summarise what has been learned so far about neutrino oscillation experiments and discuss several experimental surprises. Finally, we will turn to the future, focusing on neutrino questions that will be addressed by the search for neutrinoless double beta decay.

[slides(B)]

24/02/2012 : Prof. Ben Allanach, Cambridge

LHC versus SUSY

We review what last year's searches mean for supersymmetry, focusing on what they mean in terms of naturalness and fits to indirect data.

[slides]

17/02/2012 : Dr. Morgan Wascko, Imperial

T2K's First Neutrino Oscillation Result

The discovery of non-zero neutrino mass, via neutrino flavor oscillation, is the only confirmed observation of physics beyond the standard model of particle physics. Neutrino oscillation experiments have so far measured two of three mixing angles. I will describe the T2K experiment, a long baseline accelerator neutrino experiment in Japan searching for the third mixing angle, and present our first neutrino oscillation results.

[slides]

10/02/2012 : Dr. Sarah Bridle, UCL

Quantifying Dark Energy using Cosmic Lensing

I will describe the great potential and possible limitations of using the bending of light by gravity (gravitational lensing) to constrain the mysterious dark energy which seems to dominate the contents of our Universe. In particular we have to remove the blurring effects of our telescopes and the atmosphere to extreme precision, and account for possibly coherent distortions of galaxy shapes due to processes in galaxy formation. I will discuss these issues in more detail and review some recent progress in tackling them, putting them into the context of the upcoming Dark Energy Survey.

[slides]

03/02/2012 : Prof. Dmitri Vassiliev, UCL

Is God a geometer or an analyst?

The speaker is a specialist in the analysis of partial differential equations (PDEs) and the talk is an analyst's take on theoretical physics. We address the question: why do all the main equations of theoretical physics such as the Maxwell equation, Dirac equation and the linearized Einstein equation of general relativity contain the same physical constant - the speed of light? The accepted point of view is that this is because our world was designed on the basis of geometry, with the speed of light encoded in the concept of Minkowski metric. We suggest an alternative explanation: electromagnetism, fermions and gravity are different solutions of a single nonlinear hyperbolic system.

[slides]

27/01/2012 : Dr. Chris White, Glasgow

Polarisation Studies in Ht and Wt Production

The polarisation of the top quark can be an efficient probe of new physics models. In this seminar, I will focus on the associated production of a single top quark with either a charged Higgs boson or a W boson. Angular and energy observables relating to leptonic decay products of the top will be presented, which carry strong imprints of the top polarisation. These can be used to constrain the parameter space of two Higgs doublet models, as well as reduce backgrounds to either Ht or Wt production. The talk is based on arXiv:1111.0759.

[slides]

16/12/2011 : Jenny Thomas

MINOS + MINOS+, so good they named it twice

MINOS has delivered a number of important measurements which have moved the field of neutrino oscillations into the precision arena. The whole field is in a state of heightened excitement with recent results from a number of experiments which point to a large value of he mixing angle theta13. This will enable investigation of the mass hierarchy and CP violation in the experiments which are presently being constructed and being thought about. MINOS+ will be unique in its ability to probe with precision the correctness of the 3x3 PMNS mixing model which is presently assumed to be correct, both via the interference of other models on the oscillation probability over long distances and also via the search for sterile neutrinos, which would imply at least one extra neutrino family. In all cases, the next few years will be a great time for the neutrino field.

21/10/11 : Jocelyn Monroe (Royal Holloway London)

Searching for the Dark Matter Wind: Recent Progress from the DMTPC Experiment

The DMTPC directional dark matter detection experiment is a low-pressure CF4 gas time projection chamber, instrumented with charge and scintillation photon readout. This detector design strategy emphasizes reconstruction of WIMP-induced nuclear recoil tracks, in order to determine the direction of incident dark matter particles. Directional detection has the potential to make a definitive observation of dark matter using the unique angular signature of the dark matter wind, which is distinct from all known backgrounds. This talk will review the experimental technique and current status of DMTPC. 

07/10/11 : Mitesh Patel (Imperial College London)

LHCb

03/06/11 : Luca Panizzi (CNRS-IN2P3)

Lorentz violation in neutrinos from SN 1987a and MINOS

Lorentz invariance can be precisely tested using neutrinos from supernovae or long baseline experiments. I will discuss which limits can be imposed on general phemoneological parametrisations of Lorentz violation which go beyond the usual linear or quadratic power-law behaviour inspired by quantum-gravitational models.

27/05/11 : Costas Andreopoulos (RAL)

First Neutrino Oscillation Results from T2K

T2K is a front-runner, second-generation long-baseline neutrino oscillation experiment. It utilises a new and powerful, relatively pure muon-neutrino beam produced at Japan Proton Accelerator Research Complex (JPARC). The beam is aimed almost 2 degrees off-axis from the position of the Super-Kamiokande water Cherenkov detector in western Japan, 295 km away. The experiment also benefits from a near detector complex, instrumented with finely segmented solid scintillator and TPCs, located 280 m downstream of the beam-line target. The experiment aims to accumulate 8E+21 protons-on-target over the next 5 years. At the end of this running period, T2K aims to have improved present knowledge of sin^{2} (2\theta_{13}), sin^{2} (2\theta_{23}) and \Delta m^{2}_{23} by an order of magnitude. I will present initial muon-neutrino disappearance and electron-neutrino appearance results using the dataset accumulated during the first T2K physics run (January-June 2010), which corresponds to an integrated JPARC neutrino flux exposure of 3.23E+19 protons-on-target.

20/05/11 : Clive Speake (Birmingham) -- in Maths 505 at 3pm

Experimental Gravitation

I will describe experimental work currently underway at University of Birmingham in gravitation. We are building an experimental test of the inverse square law of gravity at short ranges using a superconducting suspension. I will describe this experiment and the challenges that need to be overcome. We have used a room temperature torsion balance to search for time variations of the gravitational constant over diurnal and semidiurnal periods as predicted by Kostelecky and Tasson (PRL 010402 2009). I will report on recent results from this experiment and improvements that are underway.

13/05/11 : Tony Padilla (Nottingham)

Meddling with Einstein

Einstein gravity has reigned supreme for over 100 years, but is it right? Of course not. We know it is definitely wrong in the super Planckian regime of quantum gravity, but perhaps it is also wrong at very low energies. I give an overview of why we might want to meddle with Einstein, and how we might do so without screwing everything up. I also give a taste of some recent ideas I've had in attempting to "solve" the cosmological constant problem.

13/05/11 : Tony Padilla (Nottingham)

Modified gravity

15/04/11 : Samuel Wallon (Laboratoire de Physique Theorique)

Mueller Navelet Jets

[slides]

01/04/11 : Sam Harper (RAL)

Recent CMS Searches for Gauge Bossons Decaying into High Pt Leptons

Many new physics scenarios beyond the Standard Model predict the existence of new heavy gauge bosons decaying to electrons and muons. Evidence of these new particles has so far not been found experimentally. In 2010, the LHC made available a new energy frontier, significantly extending the potential experimental search region in these channels. In this talk I will briefly motivate these models and then describe the CMS searches for them using 40pb of 7 TeV proton-proton collision data. Finally I will conclude with the outlook for the near term future.

11/03/11 : Matthew Wing (UCL)

Proton Driven Plasma Wakefield Accelerators

04/03/11 : Guennadi Borissov (Lancaster)

Search for new sources of CP violation with DZero detector

I will review the latest results of the DZero experiment on the search for new sources of CP violation and will discuss in detail the measurement of the like-sign dimuon charge asymmetry. This result will be compared with other Tevatron studies of CP violation in Bs system.

25/02/11 : Mario Campanelli (UCL)

Jet Physics at ATLAS

04/02/11 : Gary Barker (University of Warwick)

Liquid Argon Detectors

17/12/10 : John Baines (RAL)

Performance of the ATLAS Trigger in 2010 running

The ATLAS trigger has been used very successfully to collect collision data during 2009 and 2010 LHC running at centre-of-mass energies of 900 GeV, 2.36 TeV, and 7 TeV. The trigger system reduces the event rate, from the design bunch-crossing rate of 40 MHz, to an average recording rate of 200 Hz. The ATLAS trigger is composed of three levels. The first (L1) uses custom electronics to reject most background collisions, in less than 2.5 us, using information from the calorimeter and muon detectors. The upper two trigger levels, known collectively as the High Level Trigger (HLT), are software-based triggers. As well as triggers using global event features, such as missing transverse energy, there are selections based on identifying candidate muons, electrons, photons, tau leptons or jets. I will give an overview of the performance of these trigger selections based on extensive online running during LHC collisions and describe how the trigger has evolved with increasing LHC luminosity. I will end with a brief overview of plans for forthcoming LHC running including future trigger upgrades.

05/11/10 : Justin Evans (UCL)

Latest Results from the MINOS experiment.

The MINOS experiment uses a muon neutrino beam, over a baseline of 735 km, to measure neutrino oscillation parameters. A number of new results have been released this year. The observation of muon neutrino disappearance has allowed the world's most precise measurement of the largest neutrino mass splitting, and a competitive measurement of the mixing angle θ_23. A search for the appearance of electron neutrinos yields limits on the as-yet-unmeasured mixing angle θ_13. A measurement of the neutral current interaction rate allows limits to be placed on the existence of sterile neutrinos. Data has also been taken with a dedicated muon antineutrino beam. This data has been used to make the first precision measurement of the muon antineutrino oscillation parameters; any observed difference from the neutrino parameters would be evidence for physics beyond the standard model.

29/10/10 : Gunther Roland (MIT)

Long-range correlations in high-multiplicity proton-proton collisions at the LHC

The CMS collaboration recently announced the observation of long-range near-side angular correlations in proton-proton collisions at LHC. In this measurement, we have found a novel correlation where particles produced in the collision are aligned in their azimuthal angle over a large pseudorapidity region. This "ridge"-like structure is absent in minimum bias events but emerges as the produced particle multiplicity reaches very high values. This phenomenon has not been observed before in proton-proton collisions but resembles similar effects seen in collisions of nuclei such as copper and gold ions at RHIC. In this talk, I will report on the experimental aspects of this measurement and discuss some of the recent proposals regarding the physical origin of the effect.

08/10/10 : Adam Davison (UCL)

Exciting results from the ICHEP 2010 conference

A review of the exciting results presented at this year's International Conference on High Energy Physics in Paris this summer.

10/05/2010 : Subir Sarkar -- Monday at 4pm

Antimatter in cosmic rays: new physics or old astrophysics?

There has been considerable excitement generated by recent 'anomalies' in galactic cosmic ray and gamma-ray observations, indicative of dark matter annihilation or decay. It is essential to have a reliable evaluation of the astrophysical 'background' in order to evaluate such claims. I will focus on the PAMELA, Fermi and HESS data and discuss whether these can be accommodated in the 'standard model' of galactic cosmic ray origin and propagation or whether new physics is needed.

15/04/2010 : Krisztian Peters (University of Manchester) -- Thursday at 4pm

Higgs searches - latest results from the Tevatron

The current status of Standard Model Higgs searches at the Tevatron is presented. A comprehensive program of searches in many Higgs boson production and decay channels is underway, with recent results using up to 5.4/fb of data collected with the CDF and D0 detectors. The major contributing processes include associated production (WH→lνbb, ZH→ννbb, ZH→llbb) and gluon fusion (gg→H→WW). Improvements across the full accessible mass range resulting from the larger data sets, improved analyses techniques and increased signal acceptance will be discussed. A new CDF and D0 combined result with the updated data set will also be presented. Finally, I will discuss prospects for Higgs searches at the Tevatron.

19/03/2010 : Steve Biller (University of Oxford)

The SNO+ Project

The continuously surprising and peculiar nature of neutrinos and the weak interaction have been a source of puzzlement since they were first discovered. In recent years, a remarkable paradigm has emerged that seeks to explain hidden symmetries, the scale of neutrino masses and the reason for the imbalance between matter and antimatter in the universe. A cornerstone of this includes the notion that the physical neutrinos we see are their own antiparticles. The only viable mechanism known to have a chance of testing this is the process of neutrinoless double beta decay (0nbb). A pioneering new approach to searching for this rare process involves a novel use of the unique SNO detector in Canada as part of the SNO+ programme, which has a large UK involvement. In concert with other experiments using different isotopes, Phase I aims to convincingly establish or bound 0nbb for equivalent neutrino masses in excess ~100meV and, if seen, constrain the physics mechanism by 2015. Methods to push beyond this are also being explored. In addition, SNO+ will perform precision measurements of solar neutrinos at the transition between matter and vacuum-dominated oscillations to critically test fundamental neutrino couplings as well as studing geo-neutrinos, reactor neutrinos and a variety of other physics.

12/03/2010 : Yoshi Uchida (Imperial College London)

Charged Lepton Flavour Violation: a factor one million improvement

Flavour-changing transitions of charged leptons have been a topic of experimental investigation since the early days of particle physics, and this helped shape some of the basic laws that any successful model of particle physics would have to obey, including what we now call the Standard Model. While such phenomena have never been observed to date, when the discovery of neutrino masses and oscillations broke the Standard Model, it transformed the question "Does charged lepton flavour violation exist?" into "How much?" and "How?", and even "Why haven't we seen it yet?". In this seminar, I will describe the current experimental and theoretical state of the field, and why the next generation of experiments could hold the keys that lead the way to a fuller understanding of our universe, offering complementary discoveries that experiments at the high-energy frontier cannot reach. I will then focus on mu-e conversion experimentation, and specifically the COMET/PRISM programme which is promising a sensitivity improvement of four orders of magnitude compared to the current record, potentially improving to six orders, which could open the path to precision measurements with multiple lepton flavour-violating probes of Physics Beyond the Standard Model.

03/03/2010 14:00 : Friedrich Hehl, University of Cologne (M304 Kathleen Lonsdale Building - Origins Seminar)

Nonlocal gravity simulates dark matter

A nonlocal generalization of Einstein's theory of gravitation is constructed within the framework of the translational gauge theory of gravity. In the linear approximation, the nonlocal theory can be interpreted as linearized general relativity but in the presence of dark matter that can be simply expressed as an integral transform of matter. It is shown that this approach can accommodate the Tohline-Kuhn treatment of the astrophysical evidence for dark matter.

22/02/2010 : Friedrich Hehl, University of Cologne (Maths room 500 - Origins Seminar)

On the change in form of Maxwell's equations during the last 150 years --- spotlights on the history of classical electrodynamics ---

Starting with Maxwell's equations for the electromagnetic field (1865), we first point out how Maxwell brought his system of equations into quaternionic form. Subsequently, we recognize that what we call Maxwell's equation nowadays is a creation of Heaviside and Hertz. We touch the development of vector calculus (Hamilton, Grassmann, Gibbs, Foeppl) and of tensor calculus (Riemann, Christoffel, Ricci, Levi-Civita) both around 1900. Then we study the impact of special and of general relativity on Maxwell's equations. In particular we follow up the metric-free and topological version of Maxwell's equations via exterior differential forms and period integrals. Some alternative formulations via spinors, Clifford algebras, chains and cochains... are mentioned.

12/02/2010 : Jon Butterworth (UCL)

Subjet structure as physics tool at the LHC : and some early LHC Data

I will show some of the first jet data from the 2009 LHC run, and discuss the prospects for using jet substructure to search for new physics in high energy running.

05/02/2010 : Adrian Bevan (Queen Mary)

Super Flavour Factories: SuperB

The Standard Model of particle physics is the pinnacle of achievements of science. In one simple model we can describe the behaviour of all known particles extremely well. However we know that there are missing pieces to this puzzle. We can use SuperB to learn about the missing pieces through a multi-prong approach: i) study rare decays, ii) search forbidden decays, and iii) over-constrain measurements of Standard Model sensitive observables to see if they all agree. I will discuss just a few of the many measurements that can be made at SuperB and how these can be used to improve our understanding of particle physics. Having motivated the reasons for a new experiment, I will briefly discuss some of the aspects of such a proposed facility.

22/01/2010 : Morgan Wascko (Imperial College London)

Neutrino Cross Section Measurements at SciBooNE

As we enter the era of precision neutrino oscillation measurements, the need to improve neutrino interaction cross section measurements is paramount. SciBooNE at Fermilab uses a fine grained tracking detector to make precise neutrino and antineutrino cross section measurements on carbon and iron. I will present SciBooNE's latest physics results, which are measurement of neutral current neutral pion production by neutrinos. These measurements are of direct relevance to the future global long baseline accelerator neutrino program, especially the T2K experiment in Japan.

11/12/2009 : Alain Blondel (University of Geneva)

R&D for neutrino factory and muon collider: the MICE experiment at RAL

Neutrino Factory and Muon Collider are novel accelerators and their development is of great interest for the particle physics community. Producing, capturing and accelerating enough of these particles that live 2.2 microseconds is a challenge at every step. One of the novel technologies is ionization cooling. The Muon Ionization Cooling Experiment at RAL is set to demonstrate the feasibility and performance of a section of cooling channel on a real muon beam. After a brief introduction to the specific virtues of muon colliders and neutrino factory, the MICE experiment and its present status will be described. We will conclude with an invitation to study future possibilities.

04/12/2009 : Mark Dorman (UCL)

Preliminary CCQE Neutrino-Nucleus Scattering Results from MINOS

Charged-current quasi-elastic scattering is the dominant neutrino interaction mode at low energies and accurate knowledge of the cross section is important for current and future oscillation experiments. CCQE scattering is also hugely interesting in it's own right as a fundamental process, a probe for the axial nature of the nucleon and a window into the complex world of nuclear effects. I will first introduce the MINOS experiment and discuss CCQE scattering theory and the current status of CCQE cross section measurements. I will then present preliminary results made with a high statistics neutrino scattering dataset collected by the MINOS Near Detector.

[slides]

06/11/2009 : Henrique Araujo (Imperial College)

Direct dark matter searches with ZEPLIN-III and beyond

ZEPLIN-III is a two-phase xenon experiment deployed 1100 m underground at the Boulby mine (UK) to search for galactic dark matter WIMPs. These Weakly Interacting Massive Particles are the lead candidate to explain the missing non-baryonic matter in the universe. ZEPLIN-III operates on the principle that electron and nuclear recoils, produced in liquid xenon by different particle species, generate different relative amounts of scintillation light and ionisation charge. WIMPs are expected to scatter elastically off Xe atoms (much like neutrons), and the recoiling atom will produce a different signature to gamma-rays, which create electron recoils. The first science run at Boulby placed a 90%-confidence upper limit on the WIMP-nucleon cross-section of 8.1x10-8 pb, at the level of the world's most sensitive experiments. We are now embarking on the second run after upgrading the instrument and adding an anti-coincidence veto system. With one year of running we expect to improve our sensitivity ten-fold, biting significantly into the parameter space favoured by Supersymmetry. To fully probe the SUSY prediction requires target masses in the tonne scale and above. Achieving this whilst keeping sensitivity to nuclear recoils in the keV scale - and possibly looking for no more than a hand-full of events per year - is a serious technical challenge. This is now the priority for the most competitive technologies, namely cryogenic germanium and the noble liquids. For this next phase we have teamed up with the US LUX collaboration to deploy a tonne-scale xenon target at Homestake (South Dakota, US), possibly followed by a 20-tonne experiment. The nature of dark matter is one the main open questions in Physics today, and the race is on to claim a discovery!

30/10/2009 : Mark Lancaster (UCL)

Latest Results from CDF

The latest results from CDF since the spring of 2009, 50 in total, from the world's highest energy collisions (until the LHC beats it by 120 MeV !) at the proton anti-proton Tevatron collider will be presented. These include results on CP anomalies in the b-sector, top quark physics, searches for physics beyond the Standard Model and the latest searches for the Higgs boson.

16/10/2009 : Evgueni Goudzovski (University of Birmingham)

A precision test of lepton universality in K --> l nu decays at the CERN NA62 experiment

Measurement of the helicity-suppressed ratio of charged kaon leptonic decay rates BR(K --> e nu)/BR(K --> mu nu) has long been considered as excelent test of lepton universality and the Standard Model description of weak interactions. However it was realised only recently that the helicity suppression enhances the sensitivity to SUSY-induced effects to an experimentally accessible level. The NA62 experiment at CERN has collected a record number of over 10^5 K --> e nu decays during a dedicated run in 2007, aiming at achiving a 0.5% precision. Experimental strategy, details of the analysis, preliminary results, and future prospects of the measurement will be discussed.

[(slides)]

25/09/2009 : Geoff Mills (Subatomic Physics Group, Los Alamos National Laboaratory)

Nus and Anti-Nus from MiniBooNE

The MiniBooNE experiment, a short baseline neutrino oscillation experiment currently running at Fermilab, has spent the last two years building up its supply of anti-neutrino data, and has combed through it and the already substantial neutrino data stockpile. The intriguing results will be explored along with future possibilities for short baseline programs.

07/08/2009 : Freya Blekman (Cornell University)

CMS Pixel Detector

The Compact Muon Solenoid (CMS) is one of two general purpose experiments at the Large Hadron Collider. The CMS experiment prides itself on an ambitious, all silicon based, tracking system.

After over 10 years of design and construction the CMS tracker detector has been installed and commissioned. The tracker detector consists of ten layers of silicon microstrip detectors while three layers of pixel detector modules are situated closest to the interaction point. The pixel detector consists of 66M pixels of 100um*150um size, and is designed to use the shape of the actual charge distribution of charged particles to gain hit resolutions that will eventually be down to 12 um. This presentation will focus on commissioning activities in the CMS tracker, with extra attention on the pixel detector. Results from cosmic ray studies will be presented, in addition to results obtained from the integration of the detector within the CMS detector and various calibration and alignment analyses.

05/06/2009 : Doug Cowen (Pennsylvania State University)

Physics with IceCube's Deep Core Sub-array

The low energy reach of the IceCube Neutrino Observatory will be significantly extended with the addition of a sub-array called "DeepCore." DeepCore will be fully deployed in February 2010 in the clearest ice at the bottom center of the larger array. It will feature a 10x higher pixel density and 40% higher quantum efficiency photomultiplier tubes. It will also benefit greatly from the use of the surrounding IceCube array as an extremely effective veto against the copious background from downward-going cosmic-ray muons.

In this talk we will show that DeepCore extends the energy reach of IceCube to neutrino energies as low as 5-10 GeV. This will allow IceCube to search for lower mass solar WIMP annihilations, astrophysical neutrino sources in the southern sky, and to measure atmospheric neutrino oscillations. After an overview of IceCube and the design and deployment schedule for DeepCore, we will focus on neutrino oscillations with DeepCore. We will present some early results and predictions showing how well we can measure muon neutrino disappearance, how well we might be able to measure tau neutrino appearance, and whether we have a chance to determine the sign of the neutrino hierarchy.

15/05/2009 : Mark Dorman (UCL) -- Physics E7 at 4pm

Recent Results from the MINOS Experiment

The MINOS long baseline neutrino oscillation experiment has been taking data in the NuMI neutrino beam since 2005. In this seminar I will introduce the experiment and present the latest physics results from MINOS. I'll first discuss atmospheric neutrino mixing and then present a number of other oscillation results; the search for sterile neutrinos, the search for electron neutrino appearance (theta_13) and anti-neutrino oscillations in MINOS. Finally I'll present neutrino cross section measurements from the Near Detector and summarise the outlook for MINOS.

08/05/2009 : Peter Krizan (University of Ljubljana, Jozef Stefan Institute)

From Belle to SuperBelle

The seminar will first review some recent highlights of measurements of B and D meson properties that have been carried out by the Belle collaboration. We will discuss the motivation for a future Super B factory at KEK, as well as the requirements for the detector. Finally, the present status of the project will be presented together with the plans for the future.

01/05/2009 -- E7 at 3:15pm : Michela Massimi (UCL)

Are we justified to believe in colored quarks? A philosopher's look at the debate

24/04/2009 : Filipe Abdalla (UCL)

Neutrino Mass contstraints from cosmology

17/04/2009 : Jim Hinton (Leeds)

Gamma Ray Astronomy

27/03/2009 : Are Raklev (University of Cambridge)

Gravitino Dark Matter

20/03/2009 : Phil Harris (University of Sussex)

Testing Time Reversal

13/03/2009 : Marcella Bona (CERN)

Flavour physics as a test of the SM and a probe of new physics

The vast amount of flavour physics results delivered by the B factories and the Tevatron continuously improving Bs system measurements allows for precision test of the Standard Model (SM). The Unitarity Triangle (UT) analysis for the extraction of the CKM matrix parameters is a powerful tool for combining all the available experimental data in the flavour sector and the lattice QCD calculations to check SM consistency and determine the values of SM observables. The measurements of the UT angles recently performed at B factories provide a determination of the UT comparable in accuracy with the one performed using the other available data. Thus the UT fit is now overconstrained. It is therefore possible to add new physics (NP) contributions to all quantities entering the UT analysis and to perform a combined fit of NP contributions and SM parameters. Thus the UT fit analysis can be turned to a new physics search.

27/02/2009 -- 3pm Gustave Tuck Lecture Theatre

Origins Launch

The keynote speeches will be given by Sir Paul Nurse and Prof. John Ellis.

25/02/2009 -- Department Colloquium -- Wednesday -- Harrie Massey : Tom McLeish

13/02/2009 -- 1:30pm Maths 706

Origins -- Mathematical Foundations

23/01/2009 : Andrej Gorisek

The ATLAS Diamond PIXEL Upgrade

The goal of this project is to construct diamond pixel modules as an option for the ATLAS pixel detector upgrade. This is made possible by progress in three areas: the recent reproducible production of high quality polycrystalline Chemical Vapor Deposition diamond material in wafers, the successful completion and test of the first diamond ATLAS pixel module, and the operation of a diamond after irradiation to 1.8x10^16 p/cm2. I will summarize the results in these three areas and describe our plan to build and characterize a number of ATLAS diamond pixel modules, test their radiation hardness, explore the cooling advantages made available by the high thermal conductivity of diamond and demonstrate industrial viability of bump-bonding of diamond pixel modules.

05/12/2008
Prof. Alain Blondel (University of Geneva)

Status of MICE

28/11/2008
Harry van der Graaf

Alternative ATLAS Upgrade?

31/10/2008
Dr Robert Flack

Results from Neutrino '08

In May 2008 I attended the conference Neutrino08 in Christchurch New Zealand and gave a plenary talk about the latest results from NEMO 3 and SuperNEMO. There were approximately fifty plenary talks and 100 "beer and pizza" talks in the evening. I will give a summary of the main plenary talks.

24/10/2008
Simon Bevan

Ultra High Energy Neutrino Astronomy with ACoRNE

An overview of UHE neutrino astronomy will be presented emphasising on the exciting new results from ACoRNE. The ACoRNE collaboration has successfully been taking data from the Rona array since December 2005. Here the progress in match filters, co-incident pulse finding tools, and neural networks will be discussed, showing the development of a successful reduction and analysis package used on the Rona data. The results of this analysis will be presented as the UK's first acoustic limit.

17/10/2008
Prof. Gary Varner (University of Hawai'i)

Microwave Radio Detection of UHE Air Showers

Extensive air showers deposit such large amounts of energy into the atmosphere that even relatively weak emission mechanisms may be observable at considerable distances. It has been known since the 1960's that UHE Cosmic Ray interactions lead to a concurrent radio emission, though the process was not well understood or characterized at the time. In recent years there has been renewed interest in this lower frequency radio mechanism, attributed to geosynchrotron emission during shower evolution. However since this emission is "beamed" onto the ground, observation is similar to traditional ground array observations of the shower particles. By contrast, in analog to distant shower observation via Nitrogen fluorescence, molecular bremsstrahlung emission of shower electrons leads to isotroptic radiation at microwave radio frequencies. While incoherent emission may be detectable at kilometer scale distances, accelerator measurements indicate that at least partial coherence is present in such cascades, significantly enhancing the fiducial acceptance of this technique. Since the atmosphere is almost completely transparent to microwave and operation is insensitive to light background or weather, an order of magnitude better livetime may be expected compared with fluorescent observation, with potentially lower systematic energy uncertainty. A preliminary satellite dish-based system has been operated in Hawaii and a follow-on prototype system is described that will be deployed at the Auger Observatory in spring 2009.

10/10/2008
Prof. Yoshitaka Kuno (Osaka University)

Physics of Lepton Flavor Violation of Charged Leptons and an Experimental Proposal to Search for Muon to Electron Conversion at J-PARC

Lepton flavor violation of charged leptons has attracted much interest from theorists and experimentalists since it would have potentials to get important hints for new physics beyond the Standard Model, such as SUSY-GUT and/or SUSY-Seesaw models. In particular, a process of muon to electron conversion in a muonic atom is considered to be one of the best to search for. In this talk, a new experimental proposal to search for muon to electron conversion with sensitivity of less than 10^{-16} at J-PARC in Japan will be presented.

03/10/2008 : Dr. Chris Hays (University of Oxford)

Search for High-Mass Resonances in CDF Dimuon Data.

Neutral resonances have a long and illustrious history, and could well provide the next big discovery in particle physics. I present a new search for high-mass neutral resonances in the CDF dimuon data, the most sensitive such search to date. The analysis applies the novel technique of probing the inverse mass spectrum, for which the detector resolution is constant in the search region. The results are interpreted in terms of spin 0, 1, and 2 resonances, using sneutrino, Z', and graviton models, respectively.

26/09/2008 : Jonathon Coleman (SLAC)

The Status of mixing and CP searches in the charm sector.

During 2007 the Flavor Factories surprised the physics community with unexpected results in charm-mixing. Since this time there has been several confirmations of this phenomena. I will present an overview of recent experimental results from for the $D0$ meson oscillating into its own anti-particle, (or vice versa).

19/09/2008 : Fabrizio Palla (INFN-Pisa)

Motivation and possible architechtures for a Level-1 track Trigger in CMS and the SuperLHC

13/06/2008 : Carlo Carloni Calame -- 4pm Maths 500

Electroweak radiative corrections to Drell-Yan processes at hadron colliders

The status of the electro-weak radiative corrections to Drell-Yan processes is summarized. Their impact on observables which are important for Tevatron and LHC physics is discussed. Particular emphasis will be given on their implementation in the event generator Horace.

30/05/2008 : Dave Waters (UCL) -- E7

Weighing Up the Weak Force : W Boson Mass and Width Measurements from CDF Run II

The W boson, carrier of the weak nuclear force, is the least well measured of the Standard Model's force carriers. Precision measurements of the mass and the lifetime of the W boson provide a stringent test of the Standard Model and, indirectly, allow us to probe the physics that may lie beyond the Standard Model. I present recent direct measurements of the W boson mass and width from the CDF experiment, both of which are now the single most precise measurements in the world. I discuss several of the challenges involved in performing these analyses, and outline the prospects for such measurements in the future.

16/05/2008 : Aidan Robson (University of Glasgow)

Higgs Searches at CDF

2008 is going to be significant for Higgs physics: we expect to reach 95%CL sensitivity to a 160GeV Higgs with the combined Tevatron data. I will talk about CDF's Higgs->WW analysis, focusing on techniques, set it in the context of CDF's low-mass Higgs searches, and give an outlook for the next few years.

09/05/2008 : Ken Peach (John Adams Institute for Accelerator Science -- University of Oxford and Royal Holloway University of London)

A new accelerator for advanced research and cancer therapy

Although Fixed-Field Alternating Gradient Accelerators were invented in the 1950s, they have never made any significant impact, the technology being superseded by the synchrotron. However, interest has recently been revived, particularly in Japan, where "proof of principle" proton FFAGs have been built. More recently, a new concept - the "non-scaling FFAG" - has been advanced, which offers the prospect of developing relatively compact, high acceleration rate accelerators for a variety of purposes, from neutrino factories and muon acceleration to cancer therapy. However, there are formidable technical challenges to be overcome, including resonance crossing. We have recently been awarded funding in the UK to construct a demonstrator non-scaling FFAG at the Daresbury laboratory (EMMA, the Electron Model with Many Applications), and to design a prototype machine for proton and carbon ion cancer therapy (PAMELA, the Particle Accelerator for MEdicaL Applications). I will describe some of the motivations for developing this new type of accelerator, and discuss the status of the EMMA and PAMELA projects.

02/05/2008 : Terry Sloan (Lancaster University)

Cosmic Rays and Global Warming

In this seminar I will explore the proposed link between changes in cloud cover and the changes in the rate of ionization in the atmosphere produced by the effects of solar magnetic activity on cosmic rays. I will briefly review the mechanism by which this could cause global warming,comparing it with the more conventional view of the cause arising from the increased the concentration of greenhouse gases. I will go on to describe our searches for evidence to corroborate the cosmic ray cloud cover link.

18/04/2008 : Fabio Maltoni (Université catholique de Louvain)

The ttbar invariant mass as a window on new physics

I explore in detail the physics potential of a measurement of the ttbar invariant mass distribution at the Tevatron and the LHC. First, the accuracy of the best available predictions for this observable are considered with the result that in the low invariant mass region the shape is very well predicted and could be even used to perform a top mass measurement. Second, I study the effects of an heavy s-channel resonance on the ttbar invariant mass distribution, in a model independent way and outline a simple three-step analysis towards a discovery.

14/03/2008 : Fedor Simkovic (Comenius University Bratislava)

Double Beta Decay: History, Present and Future

The properties of the neutrinos have been the most important issues in particle physics, astrophysics and cosmology. After neutrino oscillations discovery, search for neutrinoless double beta decay (0v-decay) represents the new frontiers of neutrino physics, allowing in principle to fix the neutrino mass scale, the neutrino nature (the Dirac or Majorana particles) and possible CP violation effects. Many next generation 0v-decay experiments are in preparation or under consideration. In this presentation the development in the field of nuclear double beta decay is reviewed. A connection of the 0v-decay to neutrino oscillations and other lepton number violating processes is established. The light and sterile neutrino exchange mechanisms as well as R-parity breaking mechanisms of the 0v-decay are analyzed. The problem of the reliable determination of the 0v-decay nuclear matrix elements is addressed. The possibility of boson neutrino and partially boson neutrino is studied in light of the 2v-decay data. The perspectives of the field of the double beta decay are outlined.

07/03/2008 : Dr. Tim Namsoo

A prelude to some ZEUS results to be shown at DIS08

The DIS08 conference is fast approaching and is to be hosted by UCL and Oxford University, in the UCL campus in the week starting the 7th April. The ZEUS collaboration, that operated a general purpose detector on the HERA electron-proton collider in Hamburg, and to which the UCL HEP group belongs, are preparing to send a number of results to DIS08. The number and range of these results makes covering them all in a single seminar unfeasible so instead, a subset of results, in which the speaker is involved, will be discussed. These topics will include the measurement of the longitudinal proton structure function, the energy dependence of the photoproduction cross section, studies involving the multiplicity and momentum spectra of charged hadrons in jets and three- and four-jet cross sections in photoproduction. The talk will not include final results on all of these topics but instead will motivate and discuss various aspects of the measurements at a level not possible during the conference itself due to stricter time constraints.

29/02/2008 : Dr. Chris Parkes

The LHCb Vertex Locator and the LHCb upgrade - or finishing the bicycle wheel spokes and turning it into a vespa.

LHCb is the dedicated heavy flavour physics experiment at the LHC, and is currently being commissioned. Arguably the single most critical element of the detector is the silicon vertex locator. The unique design has 40 micron pitch silicon strip detectors operated in vacuum only 8mm from the LHC beam and retracted and reinserted between each fill. It is the only LHC detector yet to have seeen beam data - the partially assembled final system having been tested in the CERN SPS. The design, testing, alignment and performance of this detector are discussed. The discovery potential of the experiment, or the measurement of the characteristics of new physics discovered during the first phase, can be significantly enhanced through the upgrade of the experiment to run at higher luminsoity. The plans for the LHCb upgrade are presented.

22/02/2008 : Dr. Steve Boyd (Warwick)

T2K - The Next Generation.

It is now a well established fact that the weak and the mass eigenstates of neutrinos are not identical. As a consequence we can observe transitions from one neutrino species to another. Over the past decade neutrino experiments have measured most of the parameters describing neutrino oscillations with ever increasing accuracy. One parameter so far eludes measurement, the so-called mixing angle theta_13. T2K is one of the next generations experiments. While it aims to improve the knowledge of some of the other parameters, its main objective is the measurement of theta_13, which is responsible for muon to electron neutrino transitions. This angle may hold the key to study CP violating effects in the lepton sector of the SM. The seminar will summarise the current status of neutrino oscillation studies, and will outline the future contributions of the T2K Experiment.

08/02/2008 : Dr. Lisa Falk-Harris

The Double Chooz Reactor theta_13 Experiment

The Double Chooz reactor experiment is the next step for neutrino oscillation measurements: It will measure, or limit, the last undetermined PMNS mixing angle, theta_13, down to an order of magnitude below the current limit. Deploying two identical detectors, one near the reactor cores and one at a distance of 1.05 km, will permit us to control the systematics to the level required to reach a sensitivity of sin^2 2theta_13 ~0.03. I will give a brief summary of our present knowledge of the neutrino mixing parameters, and a motivation for new reactor experiments. I will then describe the design and status of the Double Chooz experiment and of its detector components. Finally, I will discuss systematics, expected sensitivity and the schedule for installation and data-taking.

01/02/2008 : Dr James Libby (Oxford)

The precise determination of the unitarity triangle angle gamma: LHCb and CLEOc

The LHCb experiment will be introduced. The precise determination of gamma is a cornerstone of the LHCb physics programme; the motivation for this will be presented. Decays of the type B+ -> DK+, where the D is a D0 or a D0bar decaying to the same final state, allow a theoretically clean measurement of gamma. The prospects with LHCb for modes where the D decays to 2, 3 and 4 bodies are discussed. This discussions introduces the importance of measurements of the strong parameters of the relevent D-decays to allow precise determination of gamma and the crucial role played by quantum correlated e+e- -> psi(3770) ->D0D0bar data currently being collected by CLEOc. The CLEOc measurements essential to a precise determination of gamma are presented.

25/01/2008 : Prof. Stephen Watts (Manchester)

Data Mining and Visualisation

There are more ways to represent ones data than by using graphs, histograms and scatterplots. There are many new techniques which exploit computer technology that enable one to visualise and explore multidimensional data. The seminar will explain these ideas, show how they are related to data mining, and apply them to particle physics data analysis.

24/01/2008 -- NB: Thursday 24th in Cruciform B.09 : Prof. Peter Rowson (Stanford Linear Accelerator)

A Novel Approach to Neutrinoless Double Beta Decay - EXO.

The "Enriched Xenon Observatory", or EXO, is an ongoing experimental and R&D program to employ a new technique for the search for neutrinoless double-beta decay. The decay and detection medium is xenon enriched in the 136 isotope. A phase I experiment known as EXO200, using 200 kg of xenon enriched to 80% xenon 136, is presently being installed at the WIPP underground facility in Carlsbad, New Mexico, and is scheduled to begin data taking at the end of the coming summer. In a two year run, this liquid xenon TPC experiment will observe and study two-neutrino double beta decay in xenon for the first time, and should exceed presently available sensitivity for the neutrinoless mode. In parallel, an R&D program is underway for a future multi-tonne detector employing a laser-fluoresence based daughter-nucleus tagging scheme that should be able to reach sensitivities to the effective neutrino mass in neutrinoless double beta-decay down to the 10 meV range.

18/01/2008 : Prof. Bob Nichol (Portsmouth)

Seeing Dark Energy (slides)

Nearly 10 years ago, astronomers discovered the expansion of the Universe was accelerating driven by a mysterious quantity now know as "Dark Energy". Explaining the existence and properties of dark energy is a major challenge for physicists. In this seminar, I will review the evidence for dark energy (including my own research) and our present understanding of dark energy. I will conclude the talk with an overview of future dark energy research which will dominate cosmology for the next decade.

30/11/2007 : Borut Kersevan (University of Ljubljana, Jozef Stefan Institute)

AcerMC Monte Carlo Generator and Heavy Flavor Matching

I will present the functionality of the AcerMC Monte Carlo event generator with the emphasis of newly developed procedure for matching hard processes with parton shower approximations in the presence of heavy quarks in the initial state.

14/11/2007 : Jan Michael Rost

Department Colluquium (Massey Theatre?)

09/11/2007 : Prof. Jenny Thomas

Lepton-Photon Neutrino Results

The most exciting results at this years Lepton-Photon came from the neutrino field. I will review the talks giving special attention to Accelerator neutrino Experiments.

02/11/2007 : Dr. Chris Hill (Bristol)

Green HEP: Doing Particle Physics with Beam Switched OFF

There are numerous scenarios of physics beyond the Standard Model (e.g. split supersymmetry) which predict the production of a heavy quasi-stable particles in 14 TeV proton-proton collisions. If these particles are charged, they will lose energy via ionisation as they traverse the experimental apparatus. Consequently, if these particles are not produced with too much initial kinetic energy and their lifetime is long enough, they will come to rest in the detector. These "stopped" particles will subsequently decay at some later time, perhaps after the beam has been switched off. I will review the theoretical motivations which suggest that such particles could be copiously produced (and stopped) at the LHC. I will also discuss the status of the experimental effort to search for such particles using the CMS detector.

19/10/2007 -- Ground Floor E3/E7 : Prof. Alan Watson (Leeds)

Recent measurements on ultra-high energy cosmic rays

Knowledge about cosmic rays above 10^19 eV has greatly improved through the successful operation of the Auger Observatory in Argentina where more events above 10^18 eV have now been recorded than from the sum of all previous efforts. I will outline the reasons for interest in this field, describe the Observatory and review our latest results on the mass composition, the energy spectrum and the anisotropy of what are the highest energy particles in Nature.

17/10/2007 --Wednesday 16:30 in the Massey Theatre : Don Eigler

The Small Frontier (W.H. Bragg Lecture)

For more than twenty years, the scanning tunneling microscope has given us a kind of virtual presence in the world of atoms. This wonderful instrument not only allows us to "see" the atomic and electronic landscape, but we also can use it to build structures of our own design with individual atoms as the building blocks. In this presentation I will describe how the microscope works and give some examples of how we use it to broaden our knowledge of the physical properties of nanometer-scale structures. I will show examples of our efforts to explore ways in which future computation might be performed using atomic-scale components.

05/10/2007 : Prof. Jon Butterworth

Hot (non-neutrino) Results from the EPS Conference

22nd June 2007 : Sebastian Boeser (UCL)

Towards acoustic detection of ultra-high energy neutrinos

Detection of neutrinos with energies at the far end of the cosmic ray spectrum promises valuable insight not only on cosmological questions, but also for high-energy particle physics. However, the tiny neutrino cross-section and the small flux require target volumes in the order of 100 km^3 - and thus the development of new detection techniques. Among a variety of different target media and interaction signatures, registration of acoustic waves in the South Polar ice cap from the neutrino-induced cascades seems to be promising. The development of a setup to verify the predicted absorption length of ~10km as well as to measure the sound velocity profile and background noise is presented.

1st June 2007 : Tim Londergan (Indiana University)

How do we interpret the NuTeV result?

25th May 2007 : Tim Gershon (Warwick)

Super Flavour Factory

Recent studies have highlighted the essential role of flavour physics in searching for and understanding physics beyond the Standard Model. At the same time, advances in accelerator technology have made realistic the possibility of an e+e- machine reaching unprecedented luminosities above 1036/cm2/s1. I will summarise the opportunities presented by the SuperB project, as described in the recent Conceptual Design Report.

18th May 2007 : Jeppe R. Andersen (Cambridge)

Hard Multi-Jet Predictions from High Energy Factorisation

The dynamics of QCD (and other field theories) simplifies greatly in the so-called perturbative "high energy limit", characterised by large centre of mass energy and fixed (perturbative) transverse scales. We will present a framework based on this high energy factorisation of scattering amplitudes, which allows for the prediction of multi(>=2)-jet rates. We will present predictions for e.g. W+jets, H+jets, and pure n-jet events at the LHC and Tevatron. Finally, we will discuss recent efforts towards improving the accuracy of the calculations.

4th May 2007 : Ryan Nichol (UCL)

Ultra-High Energy Neutrino Astronomy in Antarctica

Ultra-high energy neutrino astronomy is a rapidly emerging field at the crossroads of particle physics, astronomy and astrophysics. This talk will address the history and scientific motivation of neutrino astronomy, and discus the detection mechanisms and prospects of current and currently proposed experiments. Particular attention will be paid to the ANITA project, which successfully completed a 35 day flight over Antarctica during the Austral summer of 2006/7.

20th April 2007 : Athanasios Dedes (IPPP Durham)

A Natural Nightmare for the LHC

A very simple singlet-extension of the Standard Model which results in naturally light Dirac neutrino masses may also explain the baryon asymmetry of the Universe. This extension requires breaking of a global symmetry associated with neutrinos at low energies which in turn results in a Nambu-Goldstone boson. In this talk I will discuss how the presence of this particle may completely change our view for Higgs boson searches at the LHC.

30th March 2007 : Student practice talks for the IoP conference (Details to follow)

23rd March 2007 : Vladimir Tretyak (Institute for Nuclear Research, Kiev)

Searches for rare decays in nuclear and particle physics in INR

Experiments are reviewed which were performed by the INR (Kiev) group to search for double beta decays of several isotopes, rare alpha and beta decays, and exotic charge non-conserving (CNC) processes like decays of electron, CNC beta decays and disappearance of nucleons. In particular, in the experiment with 116-CdWO_4 crystal scintillators in the Solotvina Underground Laboratory (Ukraine) the two-neutrino double beta decay of 116-Cd was observed (T1/2=2.9e19 yr) and the best limit for neutrinoless double beta decay was set (1.7e23 yr). Fourth-fold forbidden beta decay of 113-Cd was investigated (7.7e15 yr). Rare beta decay of 115-In (4e20 yr) was observed at the first time; probably, it has the lowest value of Q_beta of ~0.5 keV. Two rare alpha decays: of 180-W (1.1e18 yr) and 151-Eu (5e18 yr) were observed at the first time. Limits on exotic decays of electron, nucleons, etc. are mostly the most stringent among known world limits. Experiments were performed either independently or in collaboration with other groups.

16th March 2007 : Dr Peter Richardson (Durham)

Herwig++

After a brief recap of the basic physics of Monte Carlo event generators I will describe the development of the new Herwig++ event generator. I will concentrate on recent progress allowing the simulation of hadron-hadron events and physics improvements. I will conclude with our plans for the future.

11th May 2007 : Morgan Wascko (Imperial)

Results from the MiniBoone neutrino experiment

Results from the MiniBoone neutrino experiment, which is investigating the anomalous LSND neutrino oscillation result.

9th March 2007 : Prof. Toshimitsu Yamazaki (University of Tokyo and Japan Academy)

Quasi-stable exotic atoms, molecules and nuclei composed of antiproton, pion and kaon

In recent years, unexpectedly long-lived exotic atoms, molecules and nuclei with constituents of antiprotons, negative pion and antikaon have been discovered. The following topics will be covered in this talk: 1) Metastable antiprotonic helium composed of an antiproton, a helium nucleus and an electron as a unique interface between the particle and the antiparticle worlds. High-precision laser spectroscopy for a CPT test and quantum tunneling effect in chemical reactions. 2) Pionic nuclei as a probe for chiral symmetry restoration in nuclear medium. 3) Kaonic nuclear systems as anomalously dense bound states mediated by antikaons. Connection with kaon condensed matter and stars.

Spreadbury memorial lecture on 07 March 2007 - Harrie Massey Theatre - 16h30 : Jeff Forshaw

Does there have to be a Higgs boson?

The Large Hadron Collider (LHC) at CERN will soon turn on and it is widely expected to discover the Higgs boson: the particle responsible for the origin of mass and the missing piece in the Standard Model of particle physics. However, there is no guarantee that nature will be so obliging. This talk will explain why we expect to see a Higgs, why it may not be there and why we are so confident that in any event something new should show itself at the LHC.

2nd March 2007 : Dr Un-ki Yang (Manchester)

Precise Measurements of Top Mass at CDF ( slides )

Exceptionally on 27th Feb 2007 - 2pm - Pearson LT in Pearson building : Dr Olga Mena (Universita "La Sapienza")

Landscape & Strings in vacqua

I will talk about the high energy neutrino detection capabilities of the long-STRING-Cherenkov Icecube neutrino in ACQUA (ice), sorrounded by the beautiful Antarctica LANDSCAPE. We explore the matter-induced oscillation effects on emitted high energy neutrino fluxes, using the energy dependent ratio of electron and tau induced showers to muon tracks, in the upcoming Icecube neutrino telescope. Although the energy of supernova neutrinos lies far below the threshold for track reconstruction in long-STRING detectors a la Icecube, a supernova neutrino burst could be recorded with a signal-to-noise ratio of ~400. The black hole at the center of the galaxy is a powerful lens for supernova neutrinos. In the very special circumstance of a supernova near the extended line of sight from Earth to the galactic center, lensing could dramatically enhance the neutrino flux at Earth and stretch the neutrino pulse. The Icecube neutrino observatory could be sensitive to both effects.

23 Feb 2007 : Will Venters

A social study of the development and use of Grid for the LHC

Pegasus is a joint research project between the LSE's Information Systems Group and UCL HEP Group to explore the development and use of Grid infrastructure for the LHC. The project is funded by the EPSRC programme: "Usability challenges from e-science" and draws on the LSE group's focus on how information and communication technology influences, and is influenced, by the social context in which it is developed and used as well as by its technical characteristics. Through qualitative research the project is exploring how the variety of people involved in developing and using GridPP infrastructure collaborate. This seminar will introduce the project, its research methods and its expected contribution. We will also outline some of our initial observations from recent research at CERN, and discuss our future research plans.

16 Feb 2007 : Kostas Fountas (Imperial)

The CMS Trigger

2nd Feb 2007 : Dr Katherine George (QMUL)

It's not just about B's. Latest Results from BABAR

19th Jan 2007 : Prof. Alan Watson (Leeds)

Progress in the search for the origin of the highest energy cosmic rays

I will explain why there is interest in the highest energy cosmic rays and describe the Pierre Auger Observatory, now the premier instrument available for their study. The latest results on the energy spectrum, mass composition and arrival direction distribution will be discussed and compared with those from other groups. Some speculations about the origin of ultra high energy cosmic rays will be made.

Exceptionally on Monday 15th Jan 2007 at 4pm : Doug Gingrich (University of Alberta and TRIUMF)

Very High-Energy Gamma-Ray Astronomy with STACEE

The study of galactic and extragalactic objects using very high-energy gamma rays is an evolving field of science. New gamma-ray telescopes are allowing us to proceed from an era of simply detecting objects to an era of precision measurements of energy spectra and time profiles. Surprisingly, there is still an unexplored energy region of the electromagnetic spectrum: 10 GeV to 250 GeV. The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is reaching into this unexplored energy region to observe pulsars, supernova remnants, active galactic nuclei and gamma-ray bursts. My talk will focus on the interest of active galactic nuclei in the unexplored energy region and observations of blazars using STACEE.

12th January 2007 : Silvia Capelli (University of Milano)

CUORICINO and CUORE: bolometric experiments for Double Beta Decay research

The positive results obtained in the last few years in neutrino oscillation experiments have stimulated great interest in Neutrinoless Double Beta Decay (DBD0n) research. Cuoricino is a running 40.7 kg TeO2 bolometric experiment dedicated to the search of DBD0n of 130Te atoms.Due to the very low expeted rate for the searched decay, a extremely low level of radioactive background is mandatory, mainly in veiw of the future large mass experiment CUORE, aimed to reach a sensitivity for the neutrino Mayorana mass in the range predicted for an inverse hierarchy scheme for neutrino masses. Last results of CUORICINO and the R&D performed in order toreduce the background level to the wanted sensitivity for CUORE will be presented.

15/12/2006 : Dr Bostjan Golob (Ljubljana)

Topics in charm hadron studies at Belle

The Belle detector at the KEK-B e^+e^- B-factory proves to be an excellent experimental environment for a wide variety of measurements. Besides the study of the CP violation in the system of B mesons, various measurements of the properties of charmed hadrons are performed. A short overview of D^0 meson mixing searches, measurements of charmonium-like resonances and properties of the recently observed charm baryons will be given.

01/12/2006 : Dr Steve Fitzgerald (Culham)

Fusion energy and nanoscale materials science

I will give a brief overview of the nuclear fusion research at UKAEA Culham, and then discuss some recent work on the modelling of materials for use in the ferocious environment of a fusion reactor.

24/11/2006 : David and Tegid Fest, exceptionally 3:30-5:30 pm

Speakers include Albrecht Wagner, George Kalmus and David Wark. Refreshments will be provided.

17/11/2006 : Dr Cinzia DaVia (Brunel)

3D silicon sensors

The LHC upgrades will demand the innermost layers of the tracking detectors to withstand fluences of about 10^16 n/cm^2 with improved spatial and time resolutions. Forward physics trackers will also require to reduce as much as possible the insensitive area at the detector'e edge. Active edge 3D sensors, where the p and n type electrodes penetrate through the entire silicon bulk thickness, have proven to match these requirements. Results will be reported of their response to charged particles using radioactive sources and particle beams with LHC-compatible readout electronics. The 3D fast time response studied using 0.13 um readout electronics and their signal efficiency after an exposure to reactor neutrons equivalent to ~1.4x10^16 high energy protons per sq. cm. will be discussed.

03/11/2006 : Dr Muge Unel (Oxford)

Highlights of PhyStat

The PHYSTAT05 conference held last year in Oxford concentrated on current statistical issues in analyzing data in particle physics, astrophysics and cosmology, as a continuation of the popular PHYSTAT series at CERN (2000), Fermilab (2000), Durham (2002) and Stanford (2003). In-depth discussions on topical issues were presented by leading statisticians and researchers in their relevant fields and the latest, state-of-the-art techniques and facilities were introduced and discussed. I will summarize the conference with an attempt to highlight most of the popular and important topics which are becoming more relevant as the start-up of the LHC experiments approaches.

Slides

20/10/2006 : Dr Zornitza Daraktchieva (UCL)

Results from the MUNU experiment on neutrino-electron scattering

The MUNU detector was designed to study electron antineutrino - electron elastic scattering at low energy. The central tracking detector is a Time Projection Chamber filled with CF4 gas, surrounded by an anti-Compton detector. In this talk I will present the final analysis of the data recorded at 3 bar and 1 bar pressure. From the 3-bar data a new upper limit on the neutrino magnetic moment of 9x10^-11 at 90 % C.L. is derived. At 1-bar a Cs-137 photopeak is reconstructed by measuring both the energy and direction of the Compton electrons in the TPC.

Exceptionally on Wed 18/10/2006, 14h00 - 17h30, Gustav Tuck LT : IoP HEPP meeting at UCL

LHC - The first year

The programme and registration details can be found here

Exceptional Seminar on Monday 16/10/2006 at 4pm, E7 : Are Raklev (CERN, Bergen)

Search for Charged Metastable SUSY Particles at the LHC

06/10/2006 : Dr Mark Lancaster (UCL)

Hot results from the summer conferences

Exceptionally on Wednesday 21/06/2006 : Joey Huston (MSU)

Lessons from the Tevatron and Standard Model Benchmarks for the LHC

I will discuss results and tools from the Fermilab Tevatron and theapplication of these tools towards the understanding of the Standard Model at the LHC during the early running.

Exceptionally on Wednesday 14/06/2006, 17h30 at the Harry Massey amphitheatre : Prof. Jonathan Butterworth (UCL)

High energy collisions and fundamental physics; or why the proton is like the tardis

19/05/2006 : Patricia Vahle (UCL)

Preliminary Results Of An Accelerator Based Search For Muon-Neutrino Disappearance By The MINOS Experiment

28/04/2006 : Rick Jesik (Imperial)

Beautifully Strange Physics at DZero

The Tevatron collider experiments have a proven track record for making significant B physics measurements. The hadronic environment provides for the production of B species not readily accessible to the B-factories. One of these states, the Bs meson, is of particular interest. I will report on studies of this meson by the DZero experiment using 1 fb-1 of data. Measurements of the Bs lifetime and lifetime difference, and the first direct upper and lower bounds on the Bs mixing frequency (Delta ms) will be presented. Our measurement of the CP violation parameter in B0 mixing and decay will also be shown.

07/04/2006 : Bino Maiheu (UCL)

Hadronization at HERMES

In the HERMES experiment, situated at the HERA storage ring in Hamburg, 27.5 GeV positrons or electrons are scattered off a fixed gaseous, polarised proton target. Data taking started in 1995 and since then HERMES has produced quite some interesting results about the nucleon's internal spin structure. To disentangle the individual contributions from the different quark flavours to the total spin 1/2 of the proton, the understanding of the production of hadrons through fragmentation is very important. Hadrons in HERMES are identified using a Ring Imaging Cherenkov (RICH) detector which is capable to disentangle with high efficiency the different hadron kinds over a momentum range of 2 to 15 GeV/c. By extracting multiplicity distributions we can study the production of hadrons more closely and moreover compare to previously published results at higher energy. Quite some effort was put into obtaining model independent results using an unfolding method to correct for experimental and QED radiative smearing as well as geometrical detector acceptance and efficiency. This talk will highlight some topics of the HERMES physics program with emphasis on the extraction of multiplicity distributions.

03/03/2006 : Erkcan Ozcan (UCL)

Radiative Penguin Decays at B Factories

For two decades, radiative penguin decays have played a central role in the search for the "new physics" of the day: top-quark mass, extended TC, anomalous trilinear gauge couplings, fouth generation of quarks and so on. Today, at the brink of the LHC experiments, many phenomenology articles on beyond-the-SM physics, and essentially almost all of the SUSY related ones, again refer to constraints from the radiative penguin decays. In the last few years, the excellent luminosity provided by the B Factories have enabled high-precision measurements of these rare decays. This talk aims to give an overview of the experimental techniques used and current limits obtained, focusing particularly on the inclusive decay b->s\gamma, the most commonly encountered member of the radiative-penguin family in the SUSY literature.

Monday 27/02/2006, 5pm at the Harrie Massey Lecture Theatre - Elizabeth Spreadbury Lecture : Carlos Frenk (University of Durham)

Cosmology confronts some of the most fundamental questions in the whole of science. How and when did our universe begin? What is it made of? How did it acquire its current appearance? There has been enormous progress in the past few years towards answering these questions. For example, recent observations have established that our universe contains an unexpected mix of components that include not only ordinary atoms, but also exotic dark matter and a new form of energy called dark energy. Gigantic surveys of galaxies like one recently completed using the Anglo-Australian Telescope in Siding Spring, New South Wales, tell us how the universe is structured. Large supercomputer simulations recreate the evolution of the universe and provide the means to relate processes occuring near the beginning of the Universe with the structures seen today. A coherent picture of cosmic evolution, going back to about a micro-second after the Big Bang, is beginning to emerge. However, fundamental issues, like the nature of the dark energy, remain unresolved. These will require understanding of what went on at even earlier times.

03/02/2006 : Ilija Bizjak (UCL)

Measurement of |Vub| at Belle

The measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vub| is an important counterpart to the measurement of the CP violation parameter sin(2 phi1) in testing the Kobayashi-Maskawa mechanism of CP violation. Recent measurements managed to obtain |Vub| with a precision that is better than 10% and have shown that the theoretical and experimental methods employed can be used to further improve the measurement. I will present the current status of inclusive and exclusive measurements of |Vub| at Belle.

Exceptionally on Tuesday 10/01/2006 (4pm in A19) : Maury Goodman (Argonne National Laboratory)

Reactor experiments for neutrino studies

In their simplest form, neutrino oscillations are described by three mixing angles and two differences of mass squared. From solar and atmospheric neutrino experiments, four of the five numbers are approximately known. The fifth value, known as theta-13, is only constrained by an upper limit on its value, which was set by the reactor neutrino experiment CHOOZ. Ideas to measure or further limit this parameter are being pursused by "off-axis" accelerator neutrino experiments, and also by improving reactor neutrino disappearance experiments. Six such reactor experiments are being pursued: Double Chooz, Braidwood, Daya Bay, KASKA, RENO and Angra. The Double Chooz experiment, in a region of France along the Belgian border, will probably be the first one in operation. The prospects and status of this experiment will be described.

07/12/2005, 3.30pm. Departmental Colloquium @ Harrie Massey : James Stirling (IPPP, Durham)

Quantum Chromodynamics and High-Energy Colliders: Fundamental Physics from Non-fundamental Particles

02/12/2005, 4pm : John Ellis (CERN)

How to look for supersymmetry?

Supersymmetry is still the most promising option for physics beyond the Standard Model, and there are good chances that it could be seen at the LHC. The experimental signature most frequently considered is missing energy, but an interesting alternative is offered by models with a metastable charged particle decaying into gravitino dark matter.

25/11/2005, 4pm : Charles Loomis (LAL Orsay)

Challenges of Analysis for Grid Computing

The LCG/EGEE production service is the largest operating grid infrastructure in the world. It is currently being used by both HEP and non-HEP applications for large scale productions. However, users wanting to run analyses on the grid will bring higher expectations and more difficult requirements with them. The presentation summarizes the current state of the grid and specific areas which will need to be improved to support analysis on grid infrastructures.

23/11/2005, 4pm. Departmental Colloquium @ Harrie Massey : Jens Als-Nielsen (Niels Bohr Institute, Copenhagen)

X-Ray synchrotron radiation - glimpses from the past and of the future

It is well known that synchrotron X-ray science - or maybe more precisely science based on X-ray synchrotron radiation (SR) - has undergone a revolution within the last couple of decades. The brilliance, the figure of merit often used for SR sources, exhibits a growth rate exceeding that of Moore~Rs law for semiconductors, and this development will continue with new large-scale projects such as the free electron X-ray laser. In this talk I shall, however, emphasize another aspect of X-ray science which will have a more direct impact on our daily lives, and that is the proliferation to universities, hospitals and companies of affordable, laser based SR sources equipped with novel X-ray optics. Amongst other benefits, this combination will allow the routine clinical use of phase-contrast imaging rather than conventional absorption-contrast imaging.

11/11/2005, 4pm : Silvia Pascoli

Determining neutrino masses

In recent years strong evidence of neutrino oscillations has been found. This implies that neutrinos are massive particles. At present, we have measured the solar and atmospheric mass squared differences but the overall neutrino mass scale and the type of hierarchy are still unknown. This information is crucial for our understanding of the origin of neutrino masses. I will review the present knowledge of neutrino parameters. I will discuss the strategies for determining the absolute values of neutrino masses (absolute mass scale and type of hierarchy). In particular, I will focus on neutrinoless double beta decay and long baseline experiments and, briefly, on direct mass searches. I will finally comment on the complementarity of these different approaches.

04/11/2005, 4pm : Oliver Rosten (Southampton)

Computing in SU(N) Yang-Mills without Fixing the Gauge

A manifestly gauge invariant Exact Renormalisation Group is constructed for SU(N) Yang-Mills, in a form convenient for computation at any loop order. A diagrammatic calculus is developed which facilitates a calculation of the two-loop beta function, for the first time without fixing the gauge or specifying the details of the regularisation scheme.

Wed 26/10/2005, 6pm. Departmental Colloquium @ Harrie Massey : Steve Jones (UCL)

Did Adam meet Eve? - the view from the genes

14/10/2005, 4pm : Alan Barr (UCL)

SUSY or extra dimensions? Can we find out with ATLAS?

Two of the most widely talked-about extensions to the Standard Model are supersymmetry and extra spatial dimensions. If applicable at the TeV-scale, both could be discovered at the LHC. However the signals from some extra dimensional models share many of the properties of supersymmetric events. I discuss some recent work which shows that ATLAS has the potential to distinguish between such models.

07/10/2005, 4pm : Hans Drevermann (CERN)

Data oriented projections in the ATLAS event display ATLANTIS

Based on simulated data of the two inner 3D tracking chambers of ATLAS, it will be shown that special projections of the data allow to check and understand complicated ATLAS interactions. These projections are optimized to suit human perception. The detection of the interactions and the cleaning of high luminosity data sets containing many noisy channels will be demonstrated.

17/06/2005, 4pm : Georg Weiglein (Durham)

Higgs Physics and Supersymmetry at Present and Future Colliders

Precision tests of the electroweak Standard Model (SM) and its minimal supersymmetric extension (MSSM) are analysed, and indirect constraints on the Higgs-boson mass in the SM and the scale of supersymmetry are discussed. In the MSSM the mass of the lightest Higgs boson is not a free parameter as in the SM, and a firm upper bound can be established. The phenomenology of Higgs physics in the MSSM can differ very significantly from the SM case. The phenomenology of Higgs physics in the MSSM at the Tevatron, the LHC and the ILC is discussed. The possible interplay between the LHC and ILC in analysing the mechanism of electroweak symmetry breaking and the underlying structure of Supersymmetric models is investigated.

03/06/2005, 4pm : Edwige Tournefier (Annecy)

Gravitational waves and the VIRGO detector

Gravitational waves are predicted by general relativity but have not yet been experimentally observed. A new generation of interferometric experiments aimed at their detection, such as Virgo, is now being commissioned. After an introduction on gravitationnal waves I will give an overview of the world programme before focusing on the Virgo detector and its commissioning.

Exceptionally on Tuesday 31/05/2005, 11am at Cruciform Seminar Room 2 : Wit Busza (MIT)

Surprises from RHIC

20/05/2005, 4pm : Claire Gwenlan (Oxford)

QCD analyses of HERA data: determination of proton PDFs

13/05/2005, 4pm : Lucio Cerrito (Oxford)

Top Quark Physics at the Tevatron

The observation of top quarks is still an exclusive privilege of only two experiments operating at the Tevatron Collider. However, never forming bound states, rapidly decaying and with unmeasurably small rare decays the top may appear like a rather uninteresting specie. Or is it ? I will review the latest measurements in top physics at the Tevatron, with focus on the CDF experiment. It emerges a rich programme that is currently testing the Standard Model at the highest energy ever reached in laboratory.

06/05/2005, 4pm : Simon Dean (UCL)

Once in a lifetime: Investigating Z -> tau tau -> e mu + neutrinos at D0

The sum of signed impact parameters in a two-track system is proposed as a tool for discriminating channels with lifetime in the final state. Z ->tau tau -> e mu is shown to be a realistic process for demonstrating this effect and a signal sample is selected from the D0 RunII dataset.

22/04/2005, 4pm : Emily Nurse (UCL)

Electroweak physics at the Tevatron

Run II of the Tevatron is now well underway and results are starting to come out thick and fast. I will present the recent electroweak results from CDF and Dzero, going through one analysis in detail to give some insight into how precision measurements are done at hadron colliders.

15/04/2005, 4pm : Philip Burrows (QMUL)

The Linear Collider: microscope on physics at the TeV scale

I will discuss the power of the Linear Collider in terms of precision measurements and discovery potential for new physics at the TeV scale. I will discuss the joint potential of the Linear Collider and the LHC. I will review briefly the status of the International Linear Collider project and the UK contributions.

Exceptionally on Monday 04/04/2005, 4pm : Chris Quigg (FermiLab)

The Double Simplex; envisioning particles and interactions

Exceptionally on Tuesday 01/03/2005, 4pm : Glen Marshall

Recent results from the TWIST experiment

The TRIUMF Weak Interaction Symmetry Test (TWIST) has recently completed its first physics analyses. The results represent a significant increase in precision for two of the four Michel parameters describing the energy and angle distributions of positrons from polarized positive muon decay. This is the first step toward our eventual goal of improving upon previous determinations for three of the parameters by at least an order of magnitude, as a test the Standard Model in the purely leptonic decay interaction. TWIST uses a polarized muon beam stopping at the center of a spectrometer consisting of a low mass, high precision array of planar drift chambers in a two tesla solenoidal field. The talk will focus on the operation of the device and the methods which are used to extract the decay parameters in a reliable way. Systematic uncertainties are especially important, as they will limit the final results.

25/02/2005, 4pm : Yoshi Uchida

The KamLAND experiment

18/02/2005, 4pm : Hans Kraus (Oxford)

The CRESST Dark Matter Search

Dark Matter is one of the key issues in the field of particle-astrophysics. We understand many phenomena in great detail, but yet, we do not know what the bulk of the Universe is made of. Dark Matter and Dark Energy appear to dominate normal matter by a large factor. I summarize the astrophysics evidence we have for the existence of Dark Matter; explain how particle physics provides a good candidate for Dark Matter particles and talk about the experimental challenges one has to master in attempting to detect WIMP Dark Matter. I review the general requirements every Dark Matter experiment has to satisfy and summarize some of the physics carried out within underground laboratories. The focus of the presentation is on novel cryogenic detectors that CRESST uses to search for WIMPs. These detectors are scintillating low-temperature calorimeters operating in the milli-kelvin temperature range and providing event type recognition to distinguish between a potential signal and backgrounds. The presentation concludes with a summary on how far the world-wide search for Dark Matter has progressed.

04/02/2005, 4pm : Steward Boogert (UCL)

Physics of/at a linear e+ e- collider

28/01/2005, 4pm : Philip Harris (Sussex)

The neutron EDM experiment

03/12/2004, 4pm : Jon Butterworth (UCL)

Implications of HERA measurements for the LHC

26/11/2004, 4pm : Ofer Lahav (UCL)

Neutrinos and Cosmology

19/11/2004, 4pm : Bill Murray (RAL)

Results from MuScat

Ionization cooling is foreseen for the muon collider and neutrino factory, and is to be tested in action in the Mice experiment at RAL. The cooling effect of dedx losses is offset by multiple scattering, which is difficult to calculate and has not been measured at the appropriate muon momenta. The MuScat experiment fixes that deficiency. The results of the MuScat experiment are presented, along with details of the performance.

15/10/2004, 4pm : David Miller (UCL)

Physics at the Future Linear Collider

08/10/2004, 4pm : Nikos Konstantinidis (UCL)

The Higgs Search: Past, present and future

Almost four years after the last data from LEP, (preparation for) the search for the wholy grail of particle physics continues. Starting with a quick review of LEP's legendary contribution to the Higgs searches, I will discuss (a) the more recent progress in precision electroweak measurements and the information they provide for the SM Higgs; and (b) the expectations in the coming years from the Tevatron and the LHC.

04/06/2004, 4pm : David Evans (Birmingham)

"ALICE and the Physics of Quark Matter"

QCD predicts that hadronic matter, under extreme conditions of temperature and pressure, will undergo a phase transition into a deconfined soup of quarks and gluons called a Quark-Gluon Plasma (QGP) The University would have been in such a state some 10^-6 to 10^-5 seconds after the Big Bang. Colliding lead ions at LHC energies will produce such a QGP and the ALICE experiment will study QCD in detail under these extreme conditions.

28/05/2004, 4pm : Costas Andreopoulos (RAL)

"The MINOS experiment: Just 7 months away from the first beam event!"

MINOS is a first generation long baseline neutrino oscillation experiment designed to study the oscillation parameter space hinted at by the results of atmospheric neutrino experiments. In order to achieve this goal we plan to use two magnetized iron calorimeters with solid scintillator as active material: a 5.4 kt one in Soudan mine in Minnesota, 735 km away from an intense, low energy neutrino beam source at Fermilab, and a smaller 1 kt one just 1 km downstream of the neutrino source. Neutrino oscillation measurements will be carried on by comparing the neutrino event rates and spectra at the two detectors. In this talk, I will briefly summarize the current experimental evidence for neutrino oscillations and describe the current status of the MINOS experiment which is now very close to the end of its construction phase. I will also try to illustrate what challenges we are going to face, after the beam starts up, using highlights from my recent work in event reconstruction, event classification and neutrino interaction model tuning/validation.

21/05/2004, 4pm : Simon Dean (Manchester)

"Once in a Lifetime: Investigating Z -> tau tau -> e mu (+neutrinos) at D0"

The sum of signed impact parameters in a two-track system is proposed as a tool for discriminating channels with lifetime in the final state. Z -> tau tau -> e mu is shown to be a realistic process for studying this effect and the current best method of signal selection is presented

27/2/2004, 4pm : Todd Huffman, Oxford

"Why B Physics is Interesting, (with a CDF focus)"

We all are convinced that the Standard Model of particle interactions is not the last word in the theory of the fundamental forces of nature. There are many searches proposed and on-going to try to add data to the speculations of what lies beyond the Standard Model. I show that the study of B mesons is actually much more fascinating than the simple measurements of lifetimes and branching ratios. These particles probe some very basic questions about the nature of matter in the Universe and are already beginning to constrain the physics beyond the standard model. Using recent results from the CDF experiment at the Fermilab Tevatron, I show how the search for physics at the TeV scale can take place at the GeV scale and why CDF is, at the moment, unique in it's capability for that search.

6/2/2004, 4pm : Frank Close, Oxford

"Pentaquarks and tetraquarks: the end of the constituent quark model?"

16/1/2004, 4pm : Giacomo Polesello, Pavia/CERN

"Discovery physics with the ATLAS detector at the LHC"

We give an overview of the potential of the ATLAS detector for the discovery of new particles at the LHC, based on the expected detector performance and on the proposed analysis strategies. A special emphasis is given to the signatures predicted by supersymmetric models.

21/11/2003, 4pm : Peter Richardson (CERN/Durham) *TBC*

"Parton Shower Monte Carlos : The State of the Art"

7/11/2003, 4pm : Ben Allanach (LAPTH)

"R-parity Violating SUSY" (including SUSY primer)

24/10/2003, 4pm : Rob Edgecock (Rutherford Appleton Laboratory)

"Neutrino Factory : Physics and Prospects"

10/10/2003, 4pm : Subir Sarkar, Oxford University

"The world according to WMAP: Does cosmology now have a Standard Model?"

Recent precision observations of anisotropies in the relic 2.7 K radiation by NASA's Wilkinson Microwave Anisotropy Probe are supposed to have determined the values of cosmological parameters to a few per cent, and in particular, to have established the presence of a cosmological constant. We will discuss the assumptions that underlie these results and draw attention to alternative cosmological models which also appear to be consistent with the data.

6/6/2003, 4pm : Dr. Ruben Saakyan (UCL)

"Neutrinoless Double Beta Decay & NEMO"

30/5/2003, 4pm. ***POSTPONEDUNTIL 20/6/2003*** : Joao Seco (ICR)

"Simulations for Intensity Modulated Radiation Treatment (IMRT)"

23/5/2003, 4pm. ***POSTPONED UNTIL 13/6/2003*** : Dr. Nigel Smith (RAL)

"The search for WIMPs in the UK"

14/3/2003, 4pm : Professor Tim Sumner (Imperial College London)

"The observation of gravitational waves from space using LISA"

7/3/2003, 4pm : Ankush Mitra (Oxford University)

"LICAS: The Linear Collider Alignment and Survey Project"

14/2/2003, 4pm : Silvia Miglioranzi (University College London)

"Algorithms Designed to Measure b-quark Production at the ZEUS Experiment at HERA"

31/1/2003, 4pm : Chris Damerell (Rutherford Appleton Laboratory)

"Feedback from Vertex 2002 Conference"

20/1/2003, 4pm : Professor Karl van Bibber (Lawrence Livermore National Laboratory)

"A Large-Scale Search for Dark-Matter Axions"

29/11/2002, 4pm. ***POSTPONEDUNTIL 13/12/2002*** : Stewart Boogert (University College London)

"Introduction to Linear Collider Physics"

22/11/2002, 4pm : Dr. Jon Butterworth (University College London)

"HERA physics as a preparation for LHC"

8/11/2002, 4pm : Professor Tom Ferbel (University of Rochester & Imperial College)

"New Measurement of the Mass of the Top Quark"

11/10/2002, 4pm : Dr. Lee Thompson (University of Sheffield)

"ANTARES - a neutrino telescope in the Mediterranean" ... or ... "Diving for WIMPs - neutrino astrophysics in the Mediterranean"

5/9/2002, 4pm : Professor Paul Singer(Technion - Israel Institute of Technology)

"Rare Charm Decays and the Search for New Physics"

14/6/2002, 11am : Greg Landsberg (Brown University)

"Black Hole Production at Future Colliders and Cosmic Rays"

10/5/2002, 4pm : Steve Biller (Oxford)

"SNO : Latest Results"

22/3/2002, 4pm : Dr.Cristina Lazzeroni (Cambridge)

"CP Violation Results from NA48"

15/3/2002, 4pm : Richard Hall-Wilton (UCL)

"Charm Production in DIS at HERA"

8/3/2002, 4pm : Stefano Moretti (CERN-TH and Durham-IPPP)

"Improving the discovery potential of charged Higgs bosons at Tevatron and the LHC"

1/2/2002, 4pm : Ed McKigney (Imperial College London)

"MuScat and MICE: Steps toward a Neutrino Factory"

31/8/2001, 4pm : Ernest Ma (University of Califormia, Riverside)

Verifiable Origin of Neutrino Masses at the TeV Scale and the Muon Anomalous Magnetic Moment.

8/5/2001, 3pm : Uri Karhson (Weizmann/UCL)

Heavy Quark Production at HERA

16/3/2001, 4pm

Spreadbury Lecture

8/12/2000, 4pm : Ivan Reid (UCL)

Muons in Sulphur and Selenium

24/11/2000, 4pm : Vitaly Kudryavtsev (Sheffield)

Dark Matter searches and neutrino astrophysics.

17/11/2000, 4pm : David Miller (UCL) (In A19)

Has LEP found the Higgs?

20/10/2000, 4pm : Angela Wyatt (Manchester).

Rapidity Gaps Between Jets at HERA

13/10/2000, 4pm : Murray Moinester (Tel Aviv).

Colour Transparency and Exclusive Meson Production at COMPASS

Wednesday 23/8/2000, 2pm : Akos Csilling (UCL)

Photon Structure and More

Don't miss your chance to meet our other OPAL postdoc!

7/4/2000 Dave Waters (Oxford) (TBC)

Measuring the W at the Tevatron

20/3/2000 5:15pm The Elizabeth Spreadbury Lecture : Alan Watson, University of Leeds.

The Quest for the Origin of the Highest Energy Cosmic Rays

Cruciform Lecture Theatre No.1. Tea, squash biscuits etc in South Cloisters at 4.45

17/3/2000 Mark Hindmarsh (Sussex)

The Dynamics of Phase Transitions in the Early Universe

3/3/2000 Pedro Teixeira-Dias (Glasgow)

Higgs searches at LEP

11/2/2000 Paul Newman (Birmingham) (TBC)

Diffractive DIS at HERA.

21/1/2000 Dave Wark (Oxford/Sussex/RAL)

Status of the Sudbury Neutrino Observatory

10/12/99 : Brian Cox, Manchester

Hard Colour-Singlet Exchange at HERA and Tevatron

Note; Rearranged Date!

26/11/99 : Nigel Glover, Durham

Prompt Photon production at LEP and Tevatron

25/11/99 : Jeff Forshaw, Manchester

Is there a Higgs Boson?

2pm. Note unusual day!

12/11/99 : Roger Jones, Lancaster

Quark and Gluon Jets and Jet Shapes

5/11/99 : Antonio Soares, UCL

Medical Application of a Gamma Camera.

21/5/99 : Prof. Douglas Ross, Southampton.

Electric Dipole Moments of the Electron and Neutron as a Window on New Physics

30/3/99 (Tuesday), Darwin Theatre, 14:00, Dr. Burton Richter, SLAC.

The Future of High Energy Physics; a Personal View

Open lecture for the UK particle physics community - Sponsored by PPARC.

24/3/99 (Wednesday) : Prof. Stanislaw Jadach, CERN

How precise are MC calculations for WW final states?

19/3/99 : Dr. Jason McFall, Bristol

Status of Babar

26/2/99 : Dr. Phil Harris, Sussex

The Search for the Electric Dipole Moment of the Neutron

The discovery of an electric dipole moment of the neutron would have dramatic consequences for particle physics beyond the Standard Model; it may even help us to understand why the universe contains more matter than antimatter. The latest EDM experiment, now running in Grenoble, applies magnetic resonance techniques to stored ultracold neutrons to obtain an extraordinarily high sensitivity, while a newly-developed magnetometer based upon spin-polarised atomic mercury allows unprecedentedly low systematic uncertainties. This talk will cover the motivation behind and the technique of the measurement; the latest results will be presented, together with some ideas for the possible future evolution of the experiment.

12/2/99 : Dr. Neville Harnew, Oxford

LHCB - Detector and Physics Challenge

5/2/99 : Matthew Wing, McGill University/UCL

Semileptonic Decays in ZEUS and Open Beauty at HERA

29/1/99 : Dr. Witek Krasny, Paris/Oxford

Nuclear Options at HERA

The HERA ep collider turned out, rather unexpectedly, to be the best machine for studies of strong interaction physics in the most intriguing domain of transition between soft and hard interactions of real and virtual photons at large and small distances. This unique microscope provide means to look at quarks and gluons in a very broad range of "precisely tunable space-time volumes" and, if nuclear option is realized, using "tunable magnification" of the color forces. What are the perspectives of nuclear program at HERA? Is a curiosity driven research program for eA scattering feasible? I shall try to answer these and other questions in my seminar.

15/1/99 : Dr. John Hassard, ICSTM.

What Can Particle Physics do for DNA Sequencing?

The HEP community in the UK has suffered a large drop in real funding in the last ten years. Paradoxically, our research prospects in HEP may never have been brighter. However, there has been a remarkable drop in applicants to physics - at all levels - partly as a consequence of a perceived lack of future for the subject as a discipline in its own right. Few would dispute the long-term importance of pure research at a cultural and societal level; many consider an emphasis on short-term spin-offs to be irrelevant or even counterproductive. I will illustrate the short-term utility of physics in general and HEP in particular by discussing our biotechnology and biomedicine programmes and making the connection to pure research. My central thesis is that if we take care of the short term, the long term takes care of itself. The key is in making the connection.

14/12/98 Carsten Hensel (Hamburg University)

Beam induced Background at a Detector at a 500 GeV Electron-Positron Linear Collider

25/11/98 Aude Gehrmann-De Ridder (Karlsruhe University)

Photon structure at LEP and Linear Collider

7/10/98.

IoP Half day meeting on future physics.

30/9/1998 Jason Ward (Glasgow)

W Physics Results from ALEPH

15/9/98 Thomas Hadig (Aachen)

Measuring the Gluon Density in the Proton at H1

20/7/98 Greg Landsberg (Brown)

Search for Exotics at D0

3/6/98 David Miller (RAL) (no relation)

Heavy Quarks from Gluon Splitting at LEP

20/5/98 Marco Stratmann (Durham)

Physics at a Polarised HERA

13/5/98 Paul Dervan (UCL)

Silicon Vertex Detectors

6/5/98 Ben Allanach (RAL)

Increased Predictivity in Supersymmetry

29/4/98 Chris Llewellyn-Smith (CERN)

Colloquium - The LHC Program

22/4/1998 David Miller (UCL)

Lepton collider prospects

3/4/1998 Rajendran Raja (FNAL)

Top quark Physics results from the Tevatron

18/3/1998 Martin McDermott (Manchester)

Diffractive Heavy Quarkonium production

16/3/1998 Malcolm Longair (Cambridge)

The Enigma of the Cosmological Constant, The Elizabeth Spreadbury Lecture

11/3/1998

IoP HEPP Group Half Day at UCL on Neutrino Physics

4/3/1998 Michael Kramer (RAL)

Current status of Quarkonia Physics

18/2/1998 Paul Dervan (UCL)

The SLD vertex detector upgrade.

16/2/1998 Martin Rees (at STS)

Our Universe and Others

28/1/1998 Simon George (RHBNC)

The ATLAS SCT Trigger

21/1/1998 Prof. H. M. Chan (RAL)

Are post-GZK air showers due to strongly interacting neutrinos?

Joint with Astronomy group, in the Massey Theatre

14/1/1998 Prof. D. H. Davis

Hypernuclei

10/12/1997 Paul Dauncey (RAL)

Measuring the CKM angle gamma at BaBar

9/12/1997 Neville Harnew (Oxford)

Observation of ring patterns with a pixellated single-photon detector

The proposed LHC-B experiment at CERN will use a novel photon detection device called the hybrid Photon Detector (HPD) to recognise rings of Cherenkov light produced by high energy particles in matter. Electrons from a photocathode surface in the HPD are accelerated and detected in a silicon pad detctor. NB. This is not a Bloomsbury seminar, but one of a series organised but CAIS/Sira UCL postgrad centre. It will be at 3pm in the M.Res seminar room, 66-72 Gower St.

3/12/1997 Phil Burrows (SLAC)

Testing the Standard Model using Polarised Electrons, a Micro-vertex Detector and Particle Identification: the SLD Experiment at SLAC

19/11/1997 Prof. Ian Percival, QMW

Quantum technology and quantum foundations (Joint with Molecular and Atomic Physics, will be held in A1)

12/11/1997 Prof. Basil Hiley, Birkbeck

Alternative Quantum Mechanical Interpretations: Do they really help? (Joint with Molecular and Atomic Physics, will be held in A1)

5/11/1997 Stan Wojcicki (Stanford U.)

Brookhaven Rare Kaon Decay Experiment

22/10/1997 Herbi Dreiner (RAL)

R-parity violation

15/10/1997 Vakhtang Kartvelishvili (Manchester)

SVD Approach to Data Unfolding

Distributions measured in high energy physics experiments are usually distorted and/or transformed by various detector effects. A regularization method for unfolding these distributions is re-formulated in terms of the Singular Value Decomposition (SVD) of the response matrix. A relatively simple, yet quite efficient unfolding procedure is explained in detail. The concise linear algorithm results in a straightforward implementation with full error propagation, including the complete covariance matrix and its inverse. Several improvements upon widely used procedures are proposed, and recommendations are given how to simplify the task by the proper choice of the matrix. Ways of determining the optimal value of the regularization parameter are suggested and discussed, and several examples illustrating the use of the method are presented.

2/10/1997 Mike Seymour (RAL) THURSDAY!!

The Internal Structure of QCD Jets

24/9/1997 Jan Lauber (UCL)

Summary of Jerusalem conference (EPS97)

4th June 1997 : Mark Hayes (Bristol University)

Hard diffractive scattering in photo-production at HERA

28th May 1997 : Tony Rooke (University College London)

Summary of the Photon 97 conference

21st May 1997 : Peter F. Smith (RAL)

Measurement of the neutrino mass from supernova

14th May 1997 : Allan Skillman (University College London)

Determination of the Trilinear Gauge Couplings in WW events at LEP II at a center of mass energy of 172 GeV

26th March 1997 : John Thompson (RAL)

ALEPH LEP 2 Results

12th March 1997 - Lynne Orr (University of Rochester)

Gluon Radiation in Top Quark Production and Decay

The strong force causes quarks to radiate gluons with a large probability. Because these gluons appear in experiments as jets of hadrons which are typically indistinguishable from jets due to quarks, making sense of these experiments requires understanding gluon radiation. This is particularly important for top physics because uncertainties in future top measurements will be dominated by systematic effects associated with gluon radiation. Gluons can be radiated during both top production and decay; both processes must be taken into account. In this seminar I discuss gluon radiation in top quark production and decay at present and future colliders (both hadron and electron-positron colliders), and some implications of the results.

19th March 1997 : Claude Bourrely (Birkbeck)(UCL)

Theory of Deep inelastic scattering

25th February 1997 - Jon Butterworth (UCL)

HERA and the Leptoquark - Is the Standard Model dead ?

Results presented last week by the H1 and ZEUS experiments at DESY, Hamburg (and submitted to journals this week) have caused something of a stir. Interest focusses on comparisons between positron-proton scattering data and the predictions of the 'Standard Model' of particle physics. Anomalies are seen in the data when the four-momentum transfer is high (Q^2 > 15000 GeV^2) and the momentum fraction of the struck quark in the proton is around x = 0.5. After a simple outline of the Standard Model and of the experiments is given, the significance and implications of these anomalies will be examined.

19th February 1997 - Boris Ruskov (Oxford)

From QED to QCD -- from similarities to differences

The purpose of this lecture is to give an elementary introduction to basic ideas of the non-perturbative QCD. The universal gauge-theory description of QCD and QED will be given. Considering both models in parallel, we will explain the reason for similarities between them in the weak-coupling regime and crucial differences in the strong-coupling (non-perturbative) region. We will discuss some ideas on how these properties can be observed.

12th February 1997

No Seminar - OPAL UK Meeting

5th February 1997 : Roger Barlow (Manchester)

Why physics lectures

29th January 1997 : Jon Flynn (Southampton)

Some recent results from Lattice QCD

I review some recent lattice QCD results for quantities of phenomenological interest. After a brief consumer guide I will survey recent results for some or all of: B-meson decay constant and mixing parameter, K-meson mixing parameter, strong coupling constant, light quark masses and the lightest scalar glueball.

22nd January 1997 : Hugh Gallagher (Oxford)

New Results on Atmospheric Neutrino Oscillations from Soudan 2

27th November 1996 : Dr C. Damerell (RAL)

The international e+e- linear collider programme: physics prospects and recent design developements

The future e+e- linear collider was one of the options studied in detail at the recent Snowmass Workshop 'New Directions for High Energy Physics'. This talk (which includes material presented in the closing parallel session) summarises recent progress on the accelerator and detector design, and contrasts the physics prospects with other options discussed during the workshop.

20th November 1996 : Prof. I Percival (QMW)

Quantum mechanics, cat-fleas and gravit

By analogy with the use of Brownian motion to detect flucuations on the atomic scale, it is shown that modern matter interferometry experiments might detect fluctuations of space-time on a Planck scale, despite the small values of the Planck length and time.

13th November 1996 : Dr B. Webber (Cavendish Laboratory)

"Hadronisation" corrections to QCD observables

Predictions in perturbative QCD refer to final states consisting of quarks and gluons, rather than the hadrons actually observed in experiments. It has therefore been customary to apply `hadronization'' corrections, based on Monte Carlo models, to the theory before comparing with experiment. Although this procedure seems to fit the data quite well, the corrections applied have not been well justified theoretically. Empirically, they behave like inverse powers of a large momentum scale of the process, for example the centre-of-mass energy in e+e- annihilation or the quark mass in heavy quark processes. Recent theoretical work has suggested that such power-suppressed corrections can arise from divergences of the perturbation series at high orders, which are called `renormalons''. This talk will explore the insights into hadronization corrections that can be obtained from the renormalon approach.

6th November 1996 : Dr C. Sutton (Oxford)

Communicating science

30th October 1996 : Dr O Teryaev (Dubna and Birkbeck)

QCD single spin asymmetries in the RHIC and HERA-N programmes

23rd October 1996: Dr J. McGovern (Manchester)

Chiral symmetry in nuclei

Partial restoration in nuclear matter of the chiral symmetry of QCD is discussed together with some of its possible signals. Estimates of corrections to the leading, linear dependence of the quark condensate are found to be small, implying a significant reduction of that condensate in matter. The importance of the pion cloud for the scalar quark density of a single nucleon indicates a close connection between chiral symmetry restoration and the attractive two-pion exchange interaction between nucleons. This force is sufficiently long-ranged that nucleons in nuclear matter will feel a significant degree of symmetry restoration despite the strong correlations between them. Expected consequences of this include reductions in hadron masses and decay constants. Various signals of these effects are discussed, in particular the enhancement of the axial charge of a nucleon in matter.

16 October 1996 : Prof E. Leader (Birkbeck)

Report on the 12th Int. Symp. on High Energy Spin Physics, Amsterdam

9th October 1996 : Prof D. Miller (UCL) and Dr J. Lauber (UCL)

Report on the INternational Conference on High Energy Physics, Warsaw

Wednesday 5th June 1996 : Dr Dhiman Chakraborty (State University of New York at Stony Brook)

The current status of top physics at the Tevatron

The Tevatron accelerator at Fermilab has recently concluded a run in the collider mode before switching to the fixed-target mode of operation for the next 3 years. Each of the two collider experiments, CDF and D0, has collected over 100 pb**-1 worth of data which is about twice what the last batch of publications were based on. The first results from this full data sample have just started to come out. In the arena of top physics, both experiments have revised their calculations of production cross-section and the mass of top quarks with reduced statistical and systematic errors. These as well as some new results from more difficult final states and a breif outline of future prospects will be presented.

Wednesday 29th May 1996 : Dr Mike Charlton (University College)

AntiHydrogen

Antihydrogen was recently observed at high energies at CERN. We briefly review this experiment, but suggest that the primary motivations for studying this object, which include CPT and WEP tests, can only be addressed by its controlled production at very low energies. Techniques which will allow this are described, including the capture and cooling of antiprotons to temperatures below 20K and the accumulation of dense positron plasmas.

Wednesday 22nd May 1996 : Nick Allen (Brunel University)

Electroweak Measurements at SLD

Wednesday 15th May 1996 :Dr George Lafferty (Manchester)

Inclusive particle production in hadronic Z decay

An overview will be given of the physics results from the study of inclusive particle production in multihadronic Z decays at LEP, the primary aim of which is to reach an understanding of the non-perturbative hadronisation process in QCD. Topics covered will include: aspects of quark and gluon fragmentation; local parton-hadron duality; QCD-based models of parton hadronisation; two-particle correlations; and spin effects in fragmetation.

Wednesday 8th May 1996 : Barry Macevoy (Imperial College)

Defect kinetics in silicon detector material

A numerical kinetics model has been used to investigate the evolution of complex defects in high resistivity silicon detector material during fast neutron irradiation to levels expected at the CERN LHC. The complex V_2O is identified as a candidate for a deep-level acceptor state which gives rise to experimentally observed changes in the effective doping concentration. The importance of the initial oxygen impurity concentration in determining the radiation tolerance of the detectors is demonstrated. The characteristics of devices heavily irradiated with Colbalt 60 photons are modelled satisfactorily by using a semiconductor simulation in conjunction with the kinetics model. It is postulated that inter-defect transitions between divacancy states in the terminal damage clusters are responsible for apparent discrepancies in the modelling of data from neutron-irradiated devices. This mechanism (if correct) may have important consequences for te prospects of "defect-engineering" a radiation hard device.

Tuesday 12th December 1995 : Dr Greg Heath (Bristol)

Hunting the Higgs Boson - In a Haystack

Particle physics experiments produce enormous raw data rates. Millions of events per second must be filtered on-line to find a few dozen of interest. Filtering processors will be described and the strategies used on them, for current experiments and for the future Large Hadron Collider at CERN.

Wednesday 29th November 1995 : Dr Jeff Forshaw (Manchester)

Report on the Beijing Lepton-Photon Conference

Wednesday 22nd November 1995 : Dr Roger Phillips (DRAL)

Speculations about the KARMEN Anomaly

The KARMEN experiment, studying neutrinos from the pi+ decay chain, has found an anomaly in the time-dependence that suggests a new unstable particle x with m(x)=33.9 MeV, produced via pi -> mu+x . Could this be a new neutrino or what? Pros, cons, ifs and buts will be reviewed.

Wednesday 15th November 1995 : Dr Subir Sarkar (Oxford)

"No-crisis" for Big Bang Nucleosynthesis

The synthesis of the light elements at the end of the `first three minutes' provides the most detailed probe of physical conditions in the early universe and has proved very useful in constraining new physics, viz. the existence of new particles and forces. Recently it was claimed that the observationally inferred abundances of deuterium, helium and lithium are in fact inconsistent with even the Standard Model, thus undermining this programme. I will review the situation and argue that there is no such crisis.

Wednesday 8th November 1995 : Prof John Edgington (QMW)

Neutrino Oscillations - Weighing the Evidence

Do neutrinos possess mass? The Standard Model says no, without giving a reason. So far there is no direct and sustainable experimental evidence for mass, despite occasional hints to the contrary. To some, non-zero mass is more "natural" and cosmologists seeking missing mass have supported this theological view with enthusiasm. Massive neutrinos will have wave functions which are combinations of separate flavour eigenstates; thus production of neutrinos of one flavour and their detection as another flavour is evidence for non-zero mass. Experimental searches for neutrino oscillations will be reviewed, concentrating on the KARMEN experiment at Rutherford Appleton Laboratory and comparing it with the LSND experiment at Los Alamos National Laboratory. Some problems of drawing conclusions will be discussed, including the relevance of a Bayesian approach to data handling.

Wednesday 1st November 1995 : Dr. D. B. Stamenov (INR, Bulgarian Academy of Sciences)

Constraints on "Fixed Point" QCD from the CCFR data on DIS

Wednesday 25th October 1995 : Dr Robert Thorne (DRAL)

Report on the European Physical Society HEP Meeting, Brussels

I will attempt to summarize some of the most important and interesting developments reported at the Meeting. This is clearly a personal choice, but the topics to be discussed include: developments in perturbative QCD, particularly small x physics, high pT jets, and higher twist corrections; particle-astrophysics and the solar neutrino problem; precision measurements (particularly R_b and R_c) and calculations in the standard model, and implications for new physics; and duality in supersymmetric theories.

Wednesday 11th October 1995 : Prof John Dainton (Liverpool)

The Partonic Structure of Diffraction

Recent new measurements of the deep-inelastic scattering of electrons on protons have revealed a new layer in our understanding of the structure of the proton. At the highest possible interaction energies, which are available only at the HERA ep collider in DESY in Hamburg, new measurements have revealed a contribution which is due to the way protons interact with other hadrons. The first measurements of the short distance structure of this contribution reveal that it is partonic, and furthermore that it may be understood in terms of Quantum Chromodynamics (QCD). For the first time, deep-inelastic lepton scattering experiments are able to probe one of the oldest conundrums in physics, namely the way nucleons interact with other nucleons (often generically referred to as diffraction), and to provide measurements which elucidate an understanding in terms of QCD. The new results which lead to these conclusions are presented and discussed.

Wednesday 14th June 1995 : Jason Ward

Measurement of the Photon Structure Function at OPAL

An introduction to how photon structure is studied at an electron-positron collider is given, with motivation for such a study. The new contributions that LEP can make to the measurement of the photon structure function are discussed and the OPAL measurements are presented. These measurements are compared with theory. The photon structure function measurements that we expect from future LEP-II running are also discussed.

Wednesday 31st May 1995 : Prof. Roger Cashmore (Oxford)

The Top Quark - Discovery and Implications

The evidence for the recent discovery of the top quark at Fermilab will be reviewed and the implications for other areas of particle physics discussed. Further progress in top quark physics will be made with upgrades to the Tevatron and the construction of the LHC while a high energy linear e+/e- collider offers intriguing possibilities. These aspects will be developed and put in perspective.

Wednesday 24th May 1995 : Dr Alexei Yung (St. Petersburg / Swansea)

Why Topological Models are Relevant to Physics

An elementary introduction to what is topological field theory is given. The problem how topological models could serve physics is discussed. In particular, the idea that the physical theory could correspond to the broken phase of the topological theory is explained. The example of such breakdown phenomenon in the two dimensional topological sigma model is presented.

Wednesday 17th May 1995 : Dr Paul Harrison (Queen Mary)

A Solution to the Solar and Atmospheric Neutrino Problem

The physics of solar and atmospheric neutrinos is reviewed, and the evidence of anomolous detection rates is summarised. Vacuum neutrino oscillations are discussed and an especially simple and elegant form for the lepton mixing matrix is proposed, based on a cyclic permutation symmetry among the generations. Predictions are compared with experiment, and an excellent fit is obtained, the data requiring a hierarchical spectrum of mass-squared differences for the neutrinos. Implications for future experiments are discussed.

Wednesday 10th May 1995 : Dr Brian Foster (Bristol)

The BaBar Experiment

I will motivate the study of CP violation in the B system by the need to understand the baryone asymmetry of the Universe. I will discuss the possible mechanisms of CP violation and various formalisms in which to understand and express them. I will discuss the requirements for an experiment to study CP violation in the B system and then show how these are being realised in the design of the BaBar experiment at PEP-II

Wednesday 3rd May 1995 : Dr Alfred Goldhaber (Stony Brook / Cambridge)

An Open Universe from Inflation

A model is described in which inflation occurs, with many of the features customarily associated with inflation, but the universe today may still exhibit appreciable negative curvature, e.g. Omega = 0.2. This is achieved without extremely fine tuning if the inflation proceeds in two stages. The first, or old inflation, stage, is one with a local minimum in the vacuum energy associated with the inflaton field, and implies a de Sitter universe. At some point a bubble forms through a a quantum transition, with new or slow-roll inflation proceeding inside. This bubble evolves into our visible universe, and the slow roll must involve a change in the magnitude of the inflaton field of the same order as the Planck scale. Tuning in the initial value (delta Phi)/Phi around 0.01 to 0.1 would be sufficient to give agreement with current observations. The model has been presented in a recent paper by M. Bucher, A.S. Goldhaber, and N. Turok, and further developed in work by Bucher and Turok.

Wednesday 15th March 1995 : Dr Apostolos Pilaftsis (DRAL)

How Left-Right Asymmetry, Tau Polarization and Lepton Universality Constrain Unified Theories at the Z Peak

We suggest the use of a universality-breaking observable based on lepton asymmetries at the Z peak, which can efficiently constrain the parameter space of unified theories. The new observable is complementary to the common lepton-universality quantity relying on partial width differences and depends critically on the chirality of a possible non-universal Z-boson coupling to like- flavour leptons. The LEP potential of probing universality violation is discussed in representative low-energy extensions of the Standard Model (SM) that may be motivated by supersymmetric grand unified theories, such as the SM with left-handed and/or right-handed neutral isosinglets, the left-right symmetric model, and the minimal supersymmetric SM.

Wednesday 8th March 1995 : Dr Mike Green (RHBNC)

The Search for the Higgs Boson at LEP I and LEP II

One of the most important outstanding issues for the standard model is the origin of mass. The most popular mechanism for generating mass requires the existence of one or more Higgs bosons with a mass below about 1 TeV. Prior to the operation of LEP there was very little opportunity to search for these and only a very small mass range close to zero was excluded. In the first few years of LEP running the whole mass range below 60 GeV has been excluded for the minimum standard model Higgs. At LEP II the sensitivity will be extended up to at least 80 GeV and hopefully higher. Direct searches above this mass will depend on LHC. However virtual effects in electroweak processes and a direct measurement of the top mass can help pin the Higgs down to a restricted mass region

Wednesday 22nd February 1995 : Dr Werner Vogelsang (DRAL)

Prompt Photon Production at Hera

We first review the status of prompt photon production in hadronic collisions, focussing in particular on the situation at high-energy ppbar colliders, where we show how the longstanding discrepancy between data and theory at small pt/S is removed by using steep small-x parton distributrions and also by taking into account the fragmentation contribution in next-to-leading order. Then we turn to prompt photon production at HERA and study its sensitivity to the parton, in particular the gluon, content of the photon in the framework of a complete next-to-leading order calculation. Special attention is paid to the issue of isolation constraints imposed on the cross section by experiment.

Wednesday 15th February 1995 : Dr Tim Greenshaw (Liverpool)

Recent Results from H1

Wednesday 25th January 1995

The Next Collider(s) after LHC : Prof David Miller

The LHC must come first, but then what? There is important physics which other colliders can do but which LHC will find difficult or impossible. Technical and physics questions will be reviewed.

Wednesday 18th January 1995 : Dr Neville Harnew (Oxford)

Exotic Physics Searches at Hera

During the 1993 running period of the HERA e-p collider, the ZEUS and H1 detectors each recorded approximately 550 inverse picobarns of integrated luminosity. I report on searches from both experiments for particles beyond the Standard Model, in which HERA is able to explore an entirely new kinematic range. Topics considered include the hunt for direct, indirect and flavour-changing leptoquarks, predicted in extensions to the Standard Model. I will also review the status of the search for excited electrons, neutrinos and quarks, all of which are predicted in composite models. Finally, I will discuss the prospects for the discovery of SUSY at HERA, both in the R-parity conserving and R-parity violating production and decay modes.

7th December 1994 : Dr Allan Skillman

Inclusive Strange Vector and Tensor Meson Production in Hadronic Z Decays

Measurements have been made in the OPAL experiment at LEP of the inclusive production of strange vector phi(1020) and K*(892) mesons, and the neutral tensor meson K*(1430). The measurements for the vector states update previously published results based on lower statistics, while the K*(1430) rate represents the first measurement of a strange tensor state in Z0 decay. Both the overall production rates, and normalised differential cross sections for the vector states, have been compared to JETSET and HERWIG predictions. The peak positions in the xi = ln(1/xp) distributions have been measured and found to be consistent with measurements of other hadron states.

Wednesday 30th November 1994 : Dr Jeff Forshaw (DRAL)

Diffractive Vector Meson Production at Large Momentum Transfer

HERA is able to observe diffractive production of vector mesons. Their observation at large momentum transfer will provide important information regarding the nature of the pomeron in QCD

Wednesday 23rd November 1994 : Dr Nick Brook (Glasgow)

The Hadronic Final State in Deep Inelastic Scattering at Zeus

The general characteristics of the hadronic final state in deep inelastic, neutral current electron-proton interactions at ZEUS are investigated for Q2 > 10 GeV2. The general properties of events with a large rapidity gap are investigated and compared to events without a rapidity gap. The kinematic properties of the jets in 2-jet events are measured and compared to NLO calculations. Fragmentation effects are investigated in the current fragmentation region. The data are used to study QCD coherence effects in DIS and to compare with corresponding e+e- data in order to test the universality of quark fragmentation.

Wednesday 2nd November 1994 : Prof Elliot Leader

The Present Status of Polarised Deep Inelastic Scattering

The unexpected results of the EMC experiment in 1987, using a longitudinally polarised lepton beam on a longitudinally polarised hydrogen target, with its suggestion of a "spin crisis in the parton model" catalysed an enormous amount of theoretical and experimental work. What that was regarded as a trivial extension of the unpolarised case is now seen to be a rich field of its own, full of subtleties. Several new experiments reported results during 1993/4. The first data on neutrons appeared and led initially to claims that the fundamental Bjorken sum rule was violated. The seminar will cover both the theory and phenomenology .

Friday 28th October 1994 : Dr Lev Chekhtman (CERN/Novosibirsk)

Microstrip Gas Chambers - Possible Applications for X-ray Detection

Existing low-dose digital X-ray systems have much worse spatial resolution than photographic film/screen techniques. Microstrip gas chambers offer resolutions of around 100 microns and may have larger area than solid-state strip or CCD detectors.

Wednesday 26th October 1994 : Dr Robert Bingham (DRAL)

Particle Acceleration in Plasmas using High Powered Lasers

The generation of relativistic plasma waves in low density plasmas is important in the quest for producing ultra-high acceleration gradients for accelerators. At present two methods are being pursued vigorously to achieve ultra-high acceleration gradients. The first is the beat wave mechanism which uses conventional long pulses (>100 ps) modest intensity lasers (I ~ 10E14 Watts/cm2 - 10E16 Watts/cm2) and the second uses the new breed of compact high brightness lasers (< 1 ps) and intensities > 10E18 Watts/cm2. With the development of these compact short pulse high brightness lasers new areas of study for laser matter interactions is opening up. In the ultra-high intensity regime laser plasma interactions are highly nonlinear and relativistic leading to new phenomenon such as plasma wakefield excitation for particle acceleration, relativistic self-focusing, remote guiding of laser beams, harmonic generation and photon acceleration.

Friday 21st October 1994 : Dr John Hassard (IC)

Diamond Detectors: Towards the Frontiers of Technology

Diamond films are strictly insulators, but they are excellent photoconductors (and conductors of heat). As detectors for ionising particles they may be especially interesting for high-radiation environments in nuclear medicine and at future particle colliders.

Wednesday 12th October 1994 : Prof Tegid Jones, Prof David Miller, Dr Mark Thomson

Glasgow Conference Review

Tegid, David and Mark will be telling us about the highlights of that sunny week in July, north of the border.