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HEP Seminars & Vivas

19 Apr 2024

UCL HEP Seminars 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.

: Jan Michael Rost

Department Colluquium (Massey Theatre?)

: 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.

: 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.

: 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.

: 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.

: Prof. Jon Butterworth

Hot (non-neutrino) Results from the EPS Conference

: 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.

: Tim Londergan (Indiana University)

How do we interpret the NuTeV result?

: 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.

: 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.

: 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.

: 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.

: Student practice talks for the IoP conference (Details to follow)

: 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.

: 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.

: Morgan Wascko (Imperial)

Results from the MiniBoone neutrino experiment

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

: 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.

: 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.

: Dr Un-ki Yang (Manchester)

Precise Measurements of Top Mass at CDF ( slides )

: Dr Olga Mena (Universita "La Sapienza") — Pearson LT in Pearson building

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.

: 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.

: Kostas Fountas (Imperial)

The CMS Trigger

: Dr Katherine George (QMUL)

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

: 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.

: 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.

: 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.