UCL

Physics and Astronomy » High Energy Physics »

HEP Seminars & Vivas

14 Nov 2024

UCL HEP Seminars 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.

: 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. 

: Mitesh Patel (Imperial College London)

LHCb

: 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.

: 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.

: Clive Speake (Birmingham) — Maths 505

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.

: 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.

: Tony Padilla (Nottingham)

Modified gravity

: Samuel Wallon (Laboratoire de Physique Theorique)

Mueller Navelet Jets

[slides]

: 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.

: Matthew Wing (UCL)

Proton Driven Plasma Wakefield Accelerators

: 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.

: Mario Campanelli (UCL)

Jet Physics at ATLAS

: Gary Barker (University of Warwick)

Liquid Argon Detectors