The LHC at CERN began operation in 2009. It collides protons at a centre-of-mass energy of up to 14 TeV and is the highest energy machine in the world. The CMS experiment at the LHC is built to search for the Higgs Boson and all sorts of other wierd and wonderful things that might exist.
For the discovery of the Higgs Boson the CMS collaboration shared the 2013 European Physical Society High Energy and Particle Physics Division prize and our group was awarded The Imperial College President's Award for Excellence in Research 2015.
I am currently working on searches for long-lived particles, such as heavy neutral leptons, using a tagger based on a Deep Neural Network and searches for Dark Matter in the Vector Boson Fusion production channel.
I lead the UK project to upgrade the CMS detector for High-Luminosity LHC. The CMS UK groups are involved in international projects to upgrade the CMS tracker, Level-1 trigger and barrel calorimeter and in the project to construct a high-granularity tracking endcap calorimeter.
In 2010 and 2011 I coordinated searches for supersymmetry in CMS.
From 2016 - 2020 I was Project Manager for the CMS Level-1 Trigger system. Responsible for all aspects of the project, including the day-to-day operation, planning and setting priorities and long term upgrades for High-Luminosity LHC, planned for 2026 onwards. Currently I chair the CMS Trigger and DAQ (TriDAS) Institution Board. I also led the CMS UK Level-1 Trigger upgrade project for several years.
In 2012 and 2013 I coordinated the project to upgrade the L1 trigger system in CMS (Phase 1).
In 2015 and 2016 I took responsibility for coordinating and commissioning the Phase 1 upgrade to the calorimeter trigger system and coordinating UK trigger upgrade activities both for Phase 1 and Phase 2 upgrades.
I worked on the global calorimeter trigger from 2006 to 2015. I wrote parts of the simulation of the trigger, tools to analyse the performance of the trigger and optimise algorithms, and led commissioning of the trigger, writing many of the software tools required for commissioning. Later I became Project Manager of the GCT with overall responsibility for the project
In 2014 and 2015 I led the Hadron Calorimeter (HCAL) Detector Performance Group Trigger sub-group, preparing the HCAL for the restart of the LHC after Long Shutdown 1 and future upgrades.
The Deep Underground Neutrino Experiment (DUNE) is a long baseline neutrino experiment, based at Fermilab near Chicago and the Sanford Underground Research Facility in South Dakota. It's scheduled to begin operation in 2026.
I am a member of the Data Aquisition System (DAQ) consortium, where I coordinate the Control, Configuration and Monitoring system.
The HERA collider at the DESY laboratory in Hamburg collided electrons or positrons with protons from 1992 to 2007. In scattering high energy electrons or positrons off protons the quarks that make up the proton can be studied down to distances of 10-18 m. The ZEUS experiment studied events from these collisions, reconstructing the particles thrown out when the proton is broken up in order to measure the structure of the proton. A poster I made about studying the structure of the proton with the ZEUS experiment is here.
As everyone knows the devil's in the detail, so to protect members of the public from the full horror links marked with a are only accessible to members of the ZEUS collaboration.
From 2003 to 2006 I was coordinator of the ZEUS High Q2 physics group.
My last contribution to ZEUS was the measurement of electron-proton charged current deep inelastic scattering cross sections with longitudinally polarised electron beams, which is now published (see publications page).
The first measurements from HERA II were of positron-proton charged and neutral current deep inelastic scattering cross sections with a longitudinally polarised positron beam. This was the first time that the dependence of these cross sections on longitudinal polarisation had been measured and details can be found in this entry in the ZEUS database. All the gory details are available to ZEUS members here .
Some useful links to the HERA I results are below.
The electron running in 1998 and 1999 allowed us to make the first measurements of the high Q2 cross sections in electron-proton collisions and to extract the structure function xF3 from the neutral current cross sections. The positron running in 1999 and 2000 gave us the largest data sample of positron-proton collisions in HERA I and allowed us to make the most accurate measurements of the high Q2 cross sections to date. In addition the large data sample made it possible to improve the calibration of the calorimeter energy scale and energy flow, yielding smaller systematic uncertainties than previous analyses. Details can be found below.
I was nominated for the Institute of Physics High Energy Particle Physics Group 2005 prize for the work above.
The structure function measurements and also measurements of jet production can be used to constrain the parton density functions (PDFs) in the proton and determine the strong coupling constant. Results from these analyses can be found in the HEPDATA database.
I worked for a long time on triggers for structure functions and exotic processes. Some details are below.
The ZEUS central tracking detector (CTD) was a large cylindrical drift chamber. As a Ph.D. student I worked on the monitoring of the quality of the CTD data. See the CTD data quality monitoring pages for details.
Later I was an on-call expert for the CTD and grew used to being woken up in the middle of the night. See the CTD online help pages for details. I also designed and implemented a database to keep track of the electronics cards for the CTD based on mySQL and PHP. You can find it here .
Imperial College built the high voltage system for the CTD and I helped to maintain it for several years. Probably only of interest to the connosieur the CTD HV system pages .
The HERA transverse polarimeter (TPOL) measured the transverse polarisation of the HERA lepton beam by shining a circularly polarised laser beam on the lepton beam and analysing the backscattered Compton photons.
As part of the HERA upgrade in 2001 - 2002 the TPOL was upgraded to provide a high precision bunch-by-bunch measurement of the polarisation. Part of this upgrade was the development and installation of a silicon strip detector to improve the accuracy of the measurement. I was involved in the development, testing and installation of the silicon strip detector and later took responsibilty for commissioning the detector and the analysis of the data. I also built a shadow system and a cosmic-ray muon test stand at Imperial with the full silicon detector readout in order to test spares and improved electronics.
Some useful links are below:
I am collaborating with Maxeler Technologies on the application of accelerated dataflow platforms and tools to particle physics, through the ExCALIBUR-HEP and SWIFT-HEP projects. I also collaborate with the Custom Computing Research Group in the department of Computer Science at Imperial College and I am deputy director of the Imperial Centre of Excellence in High-Throughput Digital Electronics for embedded Machine Learning, hosted by the Physics Dept.
Papers as convener of the CMS Supersymmetry Physics Analysis Group:
As chair or member of CMS analysis review committees:
Older papers I have written or contributed to:
A full list of my publications can be found here.
I have also submitted several papers to past ICHEP, EPS and Lepton-Photon conferences that are now superceded by the published journal papers.
I am the coordinator of fourth year (MSci) projects. More information may be found on the Blackboard page.
From 2017 to 2020 I taught the Advanced Particle Physics course. It's a fourth year option course covering the Standard Model and beyond. All the course notes and information may be found on the Blackboard page for the course.
In addtion to lecturing and project coordination I coordinate and demonstrate in the third year undergraduate laboratory, lead first and second year group tutorials, lead third year professional skills seminars, set comprehensives exam questions, mark MSci and BSc project reports, act as associate lecturer for several courses and I am a personal tutor.
I am a member of the HEP group postgraduate admissions team. Prospective Ph.D. students can find more details here and are welcome to contact me.
From 2012 to 2018 I organised the Imperial HEP group's postgraduate lectures courses.
Information for students, including the timetable and lecture notes can be found here.
I currently set the syllabus for graduate lectures on instrumentation.
Some lectures I have given as various parts of the different courses are listed below.
An introduction to particle physics detectors and instrumentation, with a focus on collider experiments.
Part of a course covering collider physics.
Part of a course covering triggering and DAQ concepts and FPGAs.
Part of a course covering collider phenomenology and analysis techniques.
A (very) brief course on deep inelastic scattering and some QCD. Another course (C7 (b)) covers non-perturbative and phenomenological aspects, like hadronisation and jets.