UCL HEP Seminars
Seminars are generally held at 4pm on Fridays in room A1 on the top floor of the physics department
A calendar of all seminars in the Physics Department
is available on the Physics Events Calendar page.
If you use Google Calendar or similar, such as Apple iCal, it is possible to subscribe to this calendar via: XML, ICAL or HTML.
Please send suggestions for topics and/or speakers to Andreas Korn and Lucian Harland-Lang.
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.
27/01/2017 : Jan Kretzschmar (Liverpool)
Precision W and Z cross-sections and the first measurement of the W boson mass at ATLASThe 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.
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.