Last changed 11 October 2004, Susan Cooper

Thesis Topics

This is a list of potential thesis topics for students starting in Oct. 2004. The links in the list are to the further details which follow on this same page. For students starting in October 2004, we have 8 PPARC studentships to use on topics of our choice, and we expect to get additional ones specifically for Grid and accelerator physics, and one joint with RAL. These studentships provide full support to UK students. The topics for which we expect to give priority for PPARC studentships are in red in the list below. Students with other funding are welcome to apply for any of the listed topics.

Running Experiments:

Experiments in preparation:

R&D Projects:

Further details

Running experiments:

CDF

 The Collider Detector at Fermilab (CDF) is an experiment to study phenomena in proton-antiproton collisions at Fermi National Accelerator Laboratory, USA. The experiment surrounds a collision point with 2 TeV energy in the centre of mass frame. This is the highest man-made energy in the world and consequently a wide variety of thesis topics are available to students.

The Oxford group is responsible for the development and maintenance of the Level 3 trigger which will look to keep the exotic B mesons in the final data sample. B mesons are often produced by very short-lived even more exotic particles. The study of the top quark, the search for the Higgs boson, and the search for SuperSymmetric sparticles (SUSY) depend on these kinds of triggers.

Possible Thesis topics:

  • Measuring Bs mixing and lifetime measurements.
  • Limits on CP violation in Bs mesons.
  • Direct CP violation in B meson decays.
  • Searches for rare B meson decays and branching ratio measurements.
  • Precision measurements of the masses of the W and Z bosons.
  • W and Z boson cross sections and spectra. Searches for additional non-Standard Model heavy vector bosons.
  • Search for evidence of Large Extra Dimensions and non-Standard Model Physics in the B sector and in W and Z sectors.
    •

    Updated 7.11.03, T. Huffman

    CRESST

    The CRESST Dark Matter Search Experiment is based upon cryogenic detectors operating at temperatures in the milli-Kelvin region. The CRESST experiment is situated in the Gran Sasso Underground Laboratory in Italy and our main collaborators are the Max Planck Institute of Physics and the Technical University in Munich. The Oxford group's activities within CRESST are the SQUID-based detector readout system, data analysis and background studies, and the study of scintillators for future dark matter targets. The experiment is currently upgrading to its second phase of running with new detectors and a higher target mass. Some of the possible thesis topics are:
    1. Data analysis: A basic analysis program in FORTRAN exists, but we started to develop new software based on a ROOT framework (C++) to accommodate the increase of data expected from phase II of CRESST.  The analysis package should be developed further in the course of the analysis of CRESST dark matter data.
    2. A complete understanding of the backgrounds in the experiment is very important. This project involves Monte Carlo simulations (e.g. EGS) and also experiments with cryodetectors to ensure the correctness of the simulation.
    3. Scintillator studies: CRESST II detectors are based upon the simultaneous detection of phonons and scintillation light. Initially, targets made of calcium tungstate will be used, but other target materials may become important when there is a dark matter signal to be confirmed. A test facility for scintillators at low temperature has been set up already for exploration of possible future target materials.
    4. Detector readout system: During 2004, CRESST is upgrading to 66 readout channels based on single SQUID amplifiers. This approach is sufficient for target masses up to ~10kg. A further improvement in sensitivity of the experiment will involve target masses of over 100 kg with a correspondingly high number of readout channels. This will require multiplexing schemes for the readout system and new concepts in detector biasing and control.
    Thesis supervisor: Hans Kraus (h.kraus@physics.ox.ac.uk)

    Updated 21.10.03, H. Kraus

    MINOS

    MINOS is a neutrino oscillation experiment which has started data taking in 2001 with cosmic rays and expects first neutrino beam data in 2004. A description of the activities of the Oxford MINOS group can be found at the Oxford Neutrino Home Page.

    We are currently looking for a DPhil student to actively participate in the groups research program. Depending on the candidates interest there are several possible fields for DPhil thesis:

    Off-line software and analyses tools

    Within the MINOS collaboration Oxford has a strong role in the development of the MINOS off-line software and analysis tools. One of the major UK contributions to the experiment is the development of an object-oriented, C++/ROOT-based analysis framework. Possible student activities are:

    Simulations:

    Data Analysis:

    The MINOS far detector is currently taking data 700 m underground at the Soudan mine in northern Minnesota. It is the first large scale underground detector with a magnetic field and one is therefore able to separate muons from anti-muons. We will therefore be able to study the oscillations for neutrinos and anti-neutrinos produced in the upper atmosphere separately, something no other experiment can do. DPhil topics could cover

    The MINOS near detector is going to be finished and will start data taking in late 2004. This is an ideal time for new students to actively participate in the analysis of beam neutrino oscillations. Interesting topics could cover

    We are also working on near detector photo multiplier tubes, the far detector front end electronics and the MINOS time distribution system, with possibilities for student involvement.

    For further information please contact Alfons Weber (a.weber@rl.ac.uk).

    Updated 10.10.03, A.Weber

    SNO

    The SNO experiment is designed to measure the solar neutrino rate.  Its distinguishing feature is that, unlike other solar neutrino experiments, it can detect all flavours of neutrinos via a neutral current reaction.  Comparing this to the electron-neutrino rate measured by charged current reactions (by SNO as well as by other experiments) will answer the crucial question: is the Sun producing fewer electron-neutrinos than expected, or are they oscillating to other neutrino types.

    SNO started taking data in the summer of 1999.  In June 2001 and May 2002 the SNO collaboration announced their results which demonstrated for the first time that neutrino oscillation is in fact taking place. Much still needs to be done to elucidate further details of the oscillation mechanism, so there are several possible topics for a student.

    Supervisors: Nick Jelley (n.jelley@physics.ox.ac.uk) and Steve Biller (s.biller@physics.ox.ac.uk)

    Updated 21.10.02, N. Jelley

    ZEUS

    HERA is the World's only electron-proton collider. It operates with 27.5 GeV electron or positron beams on 920 GeV protons. The collider has recently been upgraded to provide higher luminosity for physics at high momentum transfer. In addition the electron/positron beam will be longitudinally polarised. Oxford is a founder member of the ZEUS general purpose experiment at HERA and the UK groups provided the central tracking chamber.  The ZEUS detector has also been upgraded with the addition of improved forward tracking and a silicon microvertex detector. Oxford provided the optical alignment system for the latter and is partially responsible for the precision offline alignment of the detector using charged particle track data.

    Our physics interests are: precision measurement of inclusive deep inelastic neutral current and charged current cross-sections and associated structure functions; the QCD analysis of these and the extraction of parton distribution functions; searches for events with isolated high transverse momentum leptons and W production; the characteristics (particle multiplicity and type, etc) of events with anomalously high transverse energy and signatures for QCD instantons. These interests are very much at the core of HERA physics. The accurate measurement and understanding of high momentum transfer cross-sections is essential for many searches of new physics beyond the standard model (apart from providing very stringent tests of the SM itself). Events with high ET and/or isolated leptons are prime candidates for 'beyond the SM' physics - and even in the SM such processes offer interesting challenges both for their experimental identification and for theoretical calculation.

    A student is likely to be involved with aspects of the alignment of the vertex detector and understanding the data taken with it.  On the physics side we are keen (a) to enhance our cross-section/structure function activities to include electroweak physics at large space-like momentum transfers; (b) to extend studies to the properties of the final states of such events, particularly those involving charm and beauty quarks; (c) to widen the study of high ET processes, with emphasis on improving particle identification methods using the MVD.

    This is an excellent time to join ZEUS at HERA as you will have the chance to participate in a running high energy experiment and do physics analysis using a range of particle measurement techniques.

    Thesis supervisors: Robin Devenish (r.devenish@physics.ox.ac.uk) and Roman Walczak (r.walczak@physics.ox.ac.uk).

    Updated 24.10.03 R. Devenish

    Experiments in preparation:

    ATLAS

     Detector Development and Physics Studies for the ATLAS Detector at LHC.

    During the next  year the ATLAS silicon tracker (SCT) will be built and sent to CERN for integration into the ATLAS Inner Detector. The four barrels of the SCT are currently being assembled and fully tested at Oxford. Oxford is also responsible for the alignment and survey of the SCT. The initial survey of the position of all the SCT modules will be performed with an X-ray system being developed in Oxford. The subsequent distortions of the detector will be tracked in real time by a novel laser alignment system based on Frequency Scanning Interferometry (FSI). The final precision alignment will combine data from the X-ray survey with the FSI alignment and with data from charged tracks in the SCT.

    An ATLAS thesis would be based on a sub-set of the following projects.

    (a) Hardware Projects

    1. Commissioning of the SCT. Evaluate the performance of the SCT during assembly at Oxford and during integration at CERN.
    2. FSI-1: Commissioning and performance evaluation of the ATLAS FSI laser system.
    3. FSI-2: Development of reference interferometry for the FSI system.
    4. X-Ray: Operation and analysis of the 3D X-Ray Survey of the ATLAS SCT.

    (b) Technical Software Projects

    1. FSI lengths: Optimisation of the 1D length reconstruction from the FSI raw data.
    2. Alignment Grids: Development of a high performance software system to calculate ATLAS tracking calibration constants from FSI grid line measurements and FEA model deflection calculations.
    3. Alignment with Tracks: develop software to use the charged particle data during SCT operation to determine the positions of all  4088 SCT modules. 
    4. Combined Alignment: Development of a software system that can combine alignment system measurements with track based alignment methods.

    (c) Physics Studies

    The initial physics efforts of the Oxford ATLAS physics group are concentrating on Standard Model physics in order to understand the detector performance and to reliably estimate the backgrounds to new physics processes such as SUSY or extra dimensions. The analysis will use large samples of fully simulated and reconstructed Monte Carlo events generated by the ATLAS Data Challenge.

    1. W and Z cross sections. Use the MC data to develop the analysis tools to measure the W and Z cross sections and to study detector performance.
    2. Top. Use the MC data to develop tools to study top quark production and decay.
    3. Parton Distribution Functions (PDF). Use the MC data to develop ways to use ATLAS data to pin down the PDFs and then study how the uncertainties  in the PDFs affect the predictions for SM backgrounds to new physics.
    4. High Pt Ws and Zs. Use the MC data to study the high Pt W and Z production and use the data to predict the SM backgrounds for new physics such as SUSY.
    5. Alignment precision and physics. The physics performance of ATLAS will be limited by the alignment precision achieved. These aim of these studies will be to investigate how much the physics reach of ATLAS is affected by the mis-alignment of the SCT and Pixel detectors.. 

    Supervisors: P. Bruckman de Rensrtrom (p.bruckman1@physics.ox.ac.uk), A. Cooper-Sarkar (a.cooper-sarkar1@physics.ox.ac.uk), C. Issaver (c.issaver1@physics.ox.ac.uk), R.B. Nickerson (r.nickerson1@physics.ox.ac.uk), J.Tseng (j.tseng1@physics.ox.ac.uk), G. Viehhauser (g.viehhauser@physics.ox.ac.uk), and T. Weidberg (t.weidberg1@physics.ox.ac.uk).

    Updated Oct 04, T. Weidberg

    LHCb

    LHCb will make precision studies of CP violation in the decay of B mesons and baryons at the CERN LHC, which collides protons at 14 TeV centre of mass energy. LHCb will constrain the unitarity of the CKM matrix and check whether or not it provides a consistent picture of the CP-violation mechanism. If it does not, then we will get an insight into new physics which must lie beyond the Standard Model.

    LHCb will soon enter the construction phase. Responsibilities of the Oxford group include the particle identification using Cherenkov ring-imaging (RICH) detectors and physics simulation. A new student would be expected to work on any combination of the following areas:

  • Performance studies of the LHCb RICH detectors, preparation for data-taking, and making very first measurements of CP violation physics;
  • Commissioning the high-speed electronics and data-acquisition for the LHCb RICH system, and debugging the system in situ;
  • Design of pattern recognition for the LHCb Cherenkov detectors, development of particle identification techniques, and a first evaluation using real data.

    • The thesis supervisor will be Neville Harnew or Guy Wilkinson. Students would usually be able to spend a year at CERN.

    Updated 10.10.03, N. Harnew

    nEDM

    CP violation and its relation to the excess of matter over anti-matter in the observed Universe remains one of the core problems in physics. A particularly sensitive probe for measuring CP violation arising from physics beyond the Standard Model is offered by searches on the static electric dipole moment of the neutron (nEDM). The nEDM experiment is carried out at the ILL in Grenoble, where an experiment operating at room temperature already exists. Probing nEDM at much improved sensitivity levels requires storing ultra-cold neutrons in superfluid helium; i.e. operating at a temperature 0.5 kelvin. The responsibility of the Oxford group in this new cryo-nEDM experiment is the controlling and measuring of the magnetic environment. We plan to use a SQUID system, similar to the one used by CRESST, to measure magnetic fields in the nano-gauss region at temperatures of. The thesis topic offered here could cover various aspects of this interesting task. Thesis supervisor: Hans Kraus (h.kraus@physics.ox.ac.uk)

    Updated 21.10.03, H. Kraus

    R&D projects:

    Grid Computing

    This is your chance to make a contribution to the development of the next generation of the Internet!

    The world-wide-web changed the way we share and distribute information but has done very little to make computing power or data storage more assessible. So the aim of the Grid is to build on existing Internet protocols and to develop 'middleware' which will allow simple and transparent use of resources wherever they may be world wide. We will also need to change our applications so that they can take advantage of the Grid infrastructure and run efficiently in this complex environment.

    There are many challenges to developing a Grid that will deliver the kind of robust, high-performance system required. Computing in the LHC era, for instance, will require computing clusters with tens of thousands of nodes, and each experiment will accumulate data at a rate of about one million gigabytes per year. To cope with this scale of computing and data, experiments will have to put globally distributed resources at the physicists fingertips. Particle physicists are therefore heavily involved in providing requirements for the Grid, in developing higher levels of the middleware, and in providing a real-world use case for the early deployment of software. They are working with researchers in computer science and many other fields, often pursuing novel solutions to these awesome challenges.

    In Oxford, we have three experiments actively involved in Grid Development: LHCb, Atlas and CDF. We have a growing group consisting of 1 lecturer, 3 full time software engineers and two E-science graduate students. We enjoy close collaboration with the computer science department in Oxford, and Grid students normally undertake some of their first-year course work within that department. Specific areas of interest for graduate students include distributed systems, system testing and validation, job submission optimisation, task monitoring and error recovery. Students work closely within the various experiments and Grid collaborations which includes many UK institutions, CERN and Fermilab. Students will be required to develop excellent programming skills and also a detailed understanding of the computational needs of big science projects. We are expecting to have more E-science studentships available to start in October 2004 so please contact us if you are interested.

    For more information see our local Grid pages or contact Ian McArthur (I.McArthur@physics.ox.ac.uk) or Jeff Tseng (J.Tseng1@physics.ox.ac.uk).

    Updated 1.12.03  I.McArthur

    LiCAS

    LiCAS is short for Linear Collider Alignment and Survey. The project develops a survey system that can be used to rapidly and automatically align accelerator components during the build stage of a future linear electron positron collider to an accuracy of O(200 microns) over distances of O(600). Refraction prevents using optical methods in open air to align the components to the required accuracy. Instead, the plan is to do the survey in 25m overlapping lengths. Our system will therefore take the form of a 25m long survey train which will travel the 30km length of the tunnel establishing a coordinate system of reference marks against which the collider components will be surveyed. The train's internal co-ordinate measurement system operates in vacuum. It uses FSI (Frequency Scanning Interferometry) and LSM (Laser Straightness Monitors) to measure absolute co-ordinates. The group closely collaborates with the DESY metrology group who are building the mechanical framework for the trains and a first prototype train will be tested at DESY towards the end of 2004.

    Several thesis topics can be accommodated on this project. Besides simulation and analysis work on the physics accessible with linear colliders (SUSY, Higgs, Multiple Gauge Boson couplings, to name just a few) the experimental work would involve aspects from the list below in proportions that would be determined from the candidate's abilities and preferences. Since the project is still at an early stage and on a fairly short time scale, all project stages (design, construction, test and implementation) are accessible for new graduate students. Thesis supervisor: Armin Reichold (a.reichold@physics.ox.ac.uk).

    The train must be able to combine all measurements from several stops and calculate the co-ordinates of the surveyed markers. This has to happen both online and offline with varying amount of calibrations being used. Different algorithms for this task need to be developed and characterised by comparison with simulated data.

    Many aspects of the system will have to be calibrated against absolute length standards. Special calibration experiments that have highly stable length standards built into them and can be used for all subsystems have to be developed.

    A fibre collimation system for FSI that enables lines of sight of up to 10m: This project requires the design of suitable collimation optics and collaboration with optics manufacturers. The influence of the optics on the distance measurement and needs to be calculated and verified. The return light power levels need to be studied too.

    The errors of FSI technique due to length drift during a measurement can be reduced by using two simultaneously tuning lasers. Many alternatives exist how these two measurements can be combined and these need be developed and compared.

    21.10.03, A. Reichold

    LCFI

    The LCFI (Linear Collider Flavour Identification) collaboration is carrying out R&D for a CCD-based vertex detector for a future linear collider. Central aspects of the programme are the development and tests of new CCD technology and its readout electronics. Furthermore, mechanical issues and the physics capabilities of the detector are being studied. Thesis topics could be based on one or a combination of these fields. Beyond their envisaged use in particle physics detectors, the CCDs that are to be developed could have applications in a wide range of fields, comprising e.g. astronomy, detection of synchrotron radiation at 3rd and 4th generation light sources and electron microscopy.

    The future linear collider environment will require the ability to drive large area devices (with a length of 12.5 cm in the final design) at high read-out frequencies (up to 50 MHz), posing technical challenges for both the CCD and the readout ASIC chip. To meet these requirements, column-parallel CCDs (CPCCDs) are being developed, which have a separate readout chain for each column. Regarding the clock drivers, the needs of being able to drive a large capacitive load and of achieving a low power dissipation, averaged over time, will have to be carefully balanced.

    In May 2003, the first signals were obtained from a first version of CPCCDs, run in a standalone mode without a readout chip being connected. Tests subsequently performed in the same mode, have shown that clock amplitudes as low as 1.9 V and readout frequencies of up to 10 MHz can be achieved at an acceptable level of charge transfer efficiency. Meanwhile, the first ASIC readout chip, developed at RAL, has been mounted on the motherboard, designed and assembled by the Oxford Central Electronics Group, and is currently being tested. The aim in the short term is to then show that a CPCCD and the readout chip work together, connected by conventional wire-bonds. This will be followed by tests of an assembly using the novel technique of bump-bonding. Over the next few years of R&D a series of new versions of the devices are planned in order to achieve the required performance specifications.

    The mechanical work is currently concentrating on methods for supporting a single CPCCD, which could be thinned to ~20 microns to reduce multiple scattering. Currently finite element analysis calculations of various support options are carried out by the Oxford Mechanical Design Office. A coordinate measuring machine at RAL, based on a laser system, allows the study of deformations and vibrations of prototypes at the micron-level.

    The physics studies are designed to determine the most desirable vertex detector geometry. The particular specifications of interest are the thickness of the detector layers and the radial distance of the inner layer from the linear collider beams. The ability to efficiently identify bottom and charm hadrons with the vertex detector will be crucial for the study of a number of important new physics processes, including those predicted by Higgs and Supersymmetric models.

    For more information contact Brian Foster  (b.foster1@physics.ox.ac.uk). Our colleagues at RAL are hoping to sponsor a joint RAL/Oxford student; for more information see http://hepwww.rl.ac.uk/ppdstudentships/lcfi.htm or contact Nicolo deGroot (n.de.groot@rl.ac.uk). You can also visit the LCFI web site (http://hepwww.rl.ac.uk/lcfi/).

    Updated 25.11.03 Dr D Jackson

    MICE and Neutrino Factory R&D

    There is very active world-wide interest in the possibility of a ''neutrino factory'', i.e. a high-intensity source of high-energy neutrinos, which could greatly improve out experimental information on neutrinos and even explore CP violation in the neutrino sector. Whereas a conventional neutrino beam is made by colliding a high energy proton beam into a target and using the neutrinos from pion decay, a neutrino factory uses the muons from pion decay. The advantage is that the muons can then be accelerated and decay to produce neutrinos at a higher energy than the initial proton beam - this allows us to design much more intense neutrino beams. A growing group of UK people are involved in this work

    There are many challenges associated with realising this idea. To accelerate the muons, they first have to be formed into bunches small enough to fit into the accelerator. At Oxford, we are concentrating on this problem which is called 'Muon Cooling'. Since the muons have a very short lifetime, we have to be quick in cooling and the only promising technique is 'ionisation cooling'. In ionisation cooling, the particles travel through a series of absorbers (blocks of material) where they lose energy by ionisation loss and r.f. cavities which restores that energy (however, only restores the energy in the longitudinal direction, hence the beam is cooled). To avoid unnecessary multiple scattering, the material of choice for the absorber is liquid hydrogen. There is also a magnetic field to keep the particles focussed and to give maximum focussing at the point where they go through the absorber. The Oxford group's studies include the following, all of which could become part of a D.Phil thesis project:

    We are part of the international MICE collaboration which is building a prototype cooling channel and will operate it in a muon beam at RAL. Oxford and RAL are collaborating on the design, construction and operation of the focus coils which surround the absorbers. The coils are superconducting magnets. We are therefore right in the middle of the part of the experiment which does the actual cooling. We have also been in close consultation with the absorber groups and in particular on the safety aspects of operating all these things together. MICE will grow into a big activity at Oxford and there is potential for a D.Phil student to work on the operational aspects of the magnet, on simulations of the beam as they go through the cooling channel, on measurements on the magnets - e.g. field mapping, on the early data collection from MICE and analysis and interpretation of the early data.

    We are also thinking about possible improvements in the design of the cooling channel. One very promising development is the idea of arranging the cooling elements in a ring. This has the advantages of being cheaper and also, tricks in the bends can lead to logitudinal cooling as well. There are many new challenges e.g. how to get the beam in and out of the ring, how to remove the larger amount of heat in the absorbers, how to design the absorbers which need to be of a particular shape to get the full benefits of the longitudinal cooling. There is also much scope for thinking up entirely new configurations to form cool bunches of muons.

    Updated 18.10.03, G.Barr

    Advanced Beam Diagnostics

    Theoretical and Experimental investigations in Accelerator Physics.

    To reach new thresholds in particle physics new accelerators are needed, in particular the proposed TeV range of e+e- linear colliders. Such machines are a challenge to our ideas and applications of electromagnetism. In Oxford a team lead by Dr George Doucas and Prof Wade Allison is working on ways of imaging the bunch shape and size which will be crucial to the luminosity or collision rate seen by such an accelerator. Such work involves the calculation of EM fields, the design of detectors, the construction of test apparatus and the taking and analysis of data and working up new ideas. A student working on this project would be expected to contribute in several of these areas as well as being part of a larger team at Oxford and elsewhere which is working on the beam delivery system for the accelerator as a whole.

    Supervisors: Wade Allison (W.Allison@physics.ox.ac.uk) and George Doucas (G.Doucas@physics.ox.ac.uk). 

    Updated 24.10.03, W. Allison

    Accelerator Physics

    The Rutherford-Appleton Laboratory is also considering offering one or two joint RAL-Oxford studentships in accelerator topics. For further information see http://www.physics.ox.ac.uk/pnp/ISIS_studentships.htm or http://www.isis.rl.ac.uk/AcceleratorTheory and contact Dr. Chris Prior (C.R.Prior@rl.ac.uk).

    Updated 18.10.02, C. Prior