Experimental Particle Physics Consolidated Grant 2019-2022

Particle physics, the quest to understand matter, forces and mass generation at the most fundamental level, is never far from the news, particularly the CERN Large Hadron Collider (LHC) and its discovery of the Higgs boson. By the start of this funding period, the LHC will be preparing for its third long run at the highest intensity and energy yet. There will also be a large data sample from previous runs under analysis. Our group has a balanced programme, exploiting the full reach of the LHC in energy and precision, as well as other aspects of the unique capabilities of the CERN accelerator complex.

Our largest activity is in the ATLAS Experiment, exploring a wide range of topics at the energy frontier including the properties of the Higgs boson and searches for physics beyond our current knowledge. We are strong on all aspects of Higgs physics and on the properties of the even more massive top quark. We will also perform measurements that test our understanding of the electroweak and strong forces. Around a billion collisions take place per second in ATLAS, whereas only a tiny fraction can be permanently recorded. Our group built, maintains and operates a major part (`L1Calo') of the custom electronics (trigger) that have to select the most interesting, reducing the data rate by a factor of 500 within two millionths of a second of collisions. As part of this funding proposal, we will commission and operate our upgraded L1Calo trigger system.

The LHC will operate for a further two decades as the world's premier energy frontier facility. An ambitious programme is underway to upgrade the accelerator in the mid-2020s, giving another huge increase in the collision rate and enabling still more sensitive searches for new phenomena. In order to cope with the event rates and radiation environments, very large-scale upgrades to the detector and its associated electronics are required. We are taking major roles in two of these. In an upgrade to the innermost charged particle tracking detector, we will be constructing intricate `silicon strip' detector modules in our `BILPA' suite of clean rooms, requiring around 8000 ultrasonic wire bonds per day. We will also be designing and constructing modules for a further upgrade to the L1Calo trigger.

Beyond ATLAS, we are an expert group on rare decays of heavy quarks. At the LHCb experiment, we are investigating the complex properties and decays of beauty quarks. Among many analysis targets, one of our specialities is the search for differences between decay rates of beauty particles involving electrons and muons, which has led to a tantalising and much-discussed apparent deviation from expectations. In the funding period, we will be studying new data and decay modes to find out whether this is a new effect or merely a very unlikely statistical fluctuation. We will also play a major role in the commissioning and operation of an important upgrade to the detector (the "RICH"), and will provide highly specialised software.

Our NA62 group studies the decays of strange particles, produced at the SPS accelerator, into ultra-rare decay modes, also to search for new physics, . Ours is one of the largest groups in the collaboration and the leading one in the UK. In the funding period, we will be busy analysing the first major NA62 data sample and contributing widely to the running of the detector, including the vital `KTAG' component that we built.

The future of particle physics also includes high statistics long baseline neutrino experiments. In the funding period, we will be applying our extensive electronics expertise to produce part of the data acquisition system for the next generation `DUNE' facility, as well as preparing for data taking.

Finally, we will continue our leadership in future plans and directions for the field and will use the BILPA for R&D into detector technologies, both for future experiments and for technology transfer, for example into Medical Physics.

The Birmingham group is internationally excellent in its outreach work, introducing particle physics to wide audiences and using the LHC in particular to capture their imagination. We provide University, UK and international leadership (eg one of us held an STFC Public Engagement Fellowship). Our work with schools (ranging from spark chamber demonstrations to a Minecraft version of the LHC) provides an exciting format for engaging students and also contributed to CPD for teachers. We have been very active at exhibitions and science festivals, notably the Royal Society Summer Exhibitions. We also regularly appear in local, national and international TV, radio and printed media. The high profile developed through particle physics outreach work has resulted a measurable increase in the numbers of students applying to study physics at University.

Our `BILPA' silicon detector laboratory enables us to pursue wide-ranging knowledge exchange and technology transfer activities. Most prominent among these is `PRaVDA' and associated projects, developing precision detectors and dosimetry for use in proton beam radiotherapy, also making extensive use of the Birmingham MC40 cyclotron for detector testing and radiation tolerance characterisation. This will continue into the future, with a view to deployment in the NHS proton therapy facilities at Christie Hospital Manchester and University College Hospital London and in private centres. We have a wide-range of related start-up activities, also involving calorimetry and micropattern gaseous detectors. Those that show the most promise will be built towards full proposals to STFC or EPSRC.

Our facilities and expertise in ultrasonic wire bonding enables us to become involved in further projects with a high potential for impact. For example, we have collaborated with other departments and institutes on implantable electrical interfaces to the nervous system, which might provide amputees with significantly increased control over prosthetic limbs and a sense of touch and of limb position. Our basic R&D programme into novel silicon sensors, particularly highly radiation tolerant ones, has wide ranging potential long-term future applications. In this context, we keep in close contact with the University's Knowledge and Technology Transfer network and with the Manufacturing Technology Catapult Centre (MTC), which was set up by the regional development agency and is part-owned by the University. In a pending bid to STFC we have teamed up with the MTC to provide a local STFC innovation hub, which will be used to engage with local industry on a wide range of projects, also linking in to Birmingham's major Quantum Technology Hub centre.

Finally we are constantly seeking opportunities to engage with International Development and Global Challenges. At a small scale this happens through scientific collaborations within our experiments. Our larger-scale ambitions include replicating aspects of the BILPA laboratory in developing countries. In this context we are currently building plans with partners in Jammu, India.