Below is a list of DPhil projects for 2021 on running experiments; potential graduate students are encouraged to contact supervisors if they have any questions with regard to these projects.

ATLAS

The new energy frontier
Alan Barr, Claire Gwenlan, Chris Hays, Todd Huffman, Richard Nickerson, Georg Viehhauser, Daniela Bortoletto, Ian Shipsey and Tony Weidberg.

During 2015-2018 the LHC delivered proton-proton collisions at record-breaking energies and luminosity. We now are producing Higgs bosons in large numbers, allowing us to enter the "precision era" of Higgs physics. Precision measurements of Higgs properties will be performed to seek evidence for physics beyond the Standard Model. Our sensitivity to the production Dark Matter and other exotic particles is also better than it has ever been before. For us this is a very exciting time, with great opportunities to discover new particles, to test theories and to explore nature at smallest scales with the most powerful accelerator in the world. The period 2019-2020 will be an exciting one, as we explore the energy frontier, and prepare hardware, software and analysis improvements for the major detector upgrades planned for the years ahead.

The Oxford ATLAS group has a world-leading physics program with major responsibilities in the areas of:

Our research activities

The ATLAS detector ran successfully during LHC operations and recorded roughly 140/fb of proton-proton collision data which has not all been analysed yet. Major responsibilities of the Oxford ATLAS group include:

Physics analyses
[**]Higgs precision measurements and searches for new physics in the Higgs sector
[**]Searches for Exotics Physics
[**]Searches for Supersymmetry

[**]Standard Model Precision Measurements
[**] Detector Performance Studies
[**]Computing
[**]R&D towards an upgraded ATLAS detector for the HL-LHC

We invite you also to view our ATLAS Oxford group's highlights
https://www2.physics.ox.ac.uk/research/atlas/highlights


Thesis topics

New PhD students are expected to work in a combination of the above areas. Each of our students spends one year or more at CERN.

LHCb

B physics and CP violation at the LHC at CERN
Neville Harnew, Malcolm John, Sneha Malde or Guy Wilkinson (guy.wilkinson@cern.ch)

LHCb makes precision studies of CP violation in the decays of beauty and charm hadrons ('heavy flavour physics') at the CERN LHC. LHCb searches for physics beyond the Standard Model by investigating departures from the unitarity of the CKM matrix and checking whether or not this provides a consistent picture of observed CP-violation. The experiment also has high sensitivity to new physics effects by looking for enhanced rates of heavy flavour decays that are otherwise very rare in the Standard Model, or in unexpected angular distributions of such decays.

The LHCb detector has already collected a wealth of data, the analysis of which will likely form a significant fraction of the doctorate work. The detector is currently being upgraded, coming online in 2022, and which will greatly increase the data collection rate. Major responsibilities of the Oxford group are on the Ring Imaging Cherenkov (RICH) counters and Vertex locator (VELO); the RICH detectors provide particle identification of pions, kaons and protons over the momentum range from 1 to 100 GeV/c, and the VELO reconstructs B-decay vertices to a precision of around 150μm. The group also leads efforts on the particle identification calibrations that are core to the real-time analysis strategy that LHCb are adapting for the start of data taking.

A new graduate student would be expected to work on a combination of the following areas:

  • Undertake a significant data analysis; the Oxford LHCb group has broad physics interests which include CP violation, b-hadron decays involving tau leptons, rare B hadronic decays, charm mixing, electroweak physics including a measurement of the W mass, and central exclusive production. A major topic of the group is the measurement of the CKM angle gamma, with special interest in the family of channels B→ D(*)0 K(*) with the D0 decaying into 2-, 3- and 4-body final states. We are also active in searching for very rare beauty and charm channels, including the B→ Dµµ family of decays. A new student could expect to work in any one of the above areas, or develop an alternative analysis effort which is commensurate with the general interests of the group.
  • Participate in the commissioning and operation of the RICH or VELO sub-systems, monitoring the performance of the detectors and their readout systems. Of particular interest is maintaining the calibration of the RICH system’s performance using real data, by selecting background-free samples of K’s and π’s from D*±→ D0 (→K π) π±, and Λ0 → pπ decays.
  • Develop hardware or simulation for future LHCb upgrades, and which also have applications for other heavy flavour experiments. This could include studies of the physics performance, characterisation and design of future hybrid pixel detectors for precise measurement of heavy-flavour-decay vertices. Alternatively a student could work on the novel prototype TORCH detector to provide enhanced low-momentum particle identification, measuring time-of-flights to a precision of 15 ps.

A subset of the LHCb group are also involved with the BESIII experiment. BESIII, located in Beijing, uses electron positron collisions to create a charm hadron factory. Despite the radically different environments of LHCb and BESIII, there is a high level of synergy between them, and the combination of results is expected to lead to significant improvements in precision and sensitivity to new physics. There are opportunities for students to be involved in this exciting new venture as a part of their DPhil activities.

Students would usually be expected to spend a year or more at CERN as well as publishing much of their thesis work in peer-reviewed journals. Further information can be obtained from any of the above people, or from the LHCb-Oxford group pages.

T2K

Tokai to Kamioka neutrino oscillation experiment
Professor Giles Barr, Professor Alfons Weber, Professor Dave Wark or Dr Xianguo Lu

The Oxford T2K group is eager for new DPhil students to join. We received our first data in November 2009 and have been taking data in both neutrino and anti-neutrino mode. The intensity of the neutrino beam is still increasing allowing for precision measurements. T2K has found the first hint that CP might not be a conserved symmetry in neutrino physics. For information about the group's activities and potential thesis analysis work, please see our research group pages.