Developing Multivariate Methods for Data Analysis (Dr Adrian Bevan)
Multivariate methods are instrumental to modern particle physics analysis. Linear discriminants, neural networks and decision trees are used in a variety of pattern matching problems ranging from low level decision making in triggers, through to particle identification that is a crucial element of any analysis, and finally high level energy flow motivated event selection distinguishing between types of signal or background. This project focusses on the development of a set of tools to facilitate multivariate analysis of different types of data. The student will develop skills in C++ coding, object oriented design and advanced statistical methods. The algorithms developed will be applied to HEP data in order to benchmark their effectiveness.
CMOS Imaging Sensors for Particle Physics Applications (Dr Adrian Bevan)
CMOS imaging sensors are attractive alternatives to conventional devices for the purpose of minimum ionising particle detection. The aim of this project is to characterise CMOS monolithic active pixel sensors, studying the performance in terms of different types of noise and gain and response to radioactive sources in the lab. This project also includes the development of software in order to fully analyse data collected in the laboratory and at test-beams.An important aspect of the project will be to explore the potential use of these devices for a Higgs Factory, in the context of the SiD detector concept collaboration.
Search for Higgs boson decays in the di-muon channel with the ATLAS detector (Dr Eram Rizvi)
The Standard Model Higgs boson has been observed in a number of decay channels including decays to other gauge bosons. There are only three accessible channels to observe the fermionic decay modes of Higgs, namely to b, \tau and \mu pairs with branching ratios predicted to be proportional to the square of the fermion masses. Observation of these decay modes is an essential part of the Higgs progamme at the LHC. The measurement of the muon decay mode is particularly interesting as it is the only opportunity to access the second generation couplings. Despite the small branching fraction the sensitivity is relatively high due to the clean experimental signature, despite the large background from Drell-Yan production Z\gamma* -> \mu\mu. An observation in this channel therefore requires the large data set expected in the run-3 of the LHC operation and techniques in machine learning to identify the Higgs signal from background.
High Precision Search for New Physics in Electroweak Decays Beyond the Weak Scale (Dr Eram Rizvi)
The search for new physics at the LHC has progressed in many directions including searches for supersymmetric particles, anomalous gauge couplings, rare decay modes, and low scale gravity phenomena to name a few. So far no deviations from the predictions of the Standard Model have been observed. Worse, the phase space for many of the models is becoming increasingly constrained. This project aims to make high precision measurements of electroweak gauge boson production in neutral and charged current modes above the weak scale. The measurements are sensitive to deviations of the propagtors and the electroweak couplings from the Standard Model expectations, which appear in effective field theories. These searches are threfore sensitive to new particles with electroweak quantum numbers but wthout any assumptions on the decay properties of the new particles. The measurements have a clean experimental signature and low backgrounds allowing high accuracy to be obtained and tests of new physics at the precision frontier of the LHC.