ERC FUNDED PROJECTS

The ability of positrons to annihilate with electrons, producing characteristic gamma rays, gives them important use in medicine via positron-emission tomography (PET), diagnostics of industrially-important materials, and in elucidating astrophysical phenomena. Moreover, the fundamental interactions of positrons and positronium (Ps) with atoms, molecules and condensed matter are currently under intensive study in numerous international laboratories, to illuminate collision phenomena and perform precision tests of fundamental laws. Proper interpretation and development of these costly and difficult experiments requires accurate calculations of low-energy positron and Ps interactions with normal matter. These systems, however, involve strong correlations, e.g., polarisation of the atom and virtual-Ps formation (where an atomic electron tunnels to the positron): they significantly effect positron- and Ps-atom/molecule interactions, e.g., enhancing annihilation rates by many orders of magnitude, and making the accurate description of these systems a challenging many-body problem. Current theoretical capability lags severely behind that of experiment. Major theoretical and computational developments are required to bridge the gap. One powerful method, which accounts for the correlations in a natural, transparent and systematic way, is many-body theory (MBT). Building on my expertise in the field, I propose to develop new MBT to deliver unique and unrivalled capability in theory and computation of low-energy positron and Ps interactions with atoms, molecules, and condensed matter. The ambitious programme will provide the basic understanding required to interpret and develop the fundamental experiments, antimatter-based materials science techniques, and wider technologies, e.g., (PET), and more broadly, potentially revolutionary and generally applicable computational methodologies that promise to define a new level of high-precision in atomic-MBT calculations.

1 318 419 €

Start date: 2019-02-01, End date: 2024-01-31

This proposal outlines a plan to combine Charge Couple Device (CCD) camera technologies with two-phase Liquid Argon Time Projection Chambers (LAr TPCs) utilising THick Gas Electron Multipliers (THGEMs) to evolve a next generation neutrino detector. This will be an entirely new readout option, and will open the prospect of revolutionary discoveries in fundamental particle physics. Furthermore, the Compton imaging power of this technology will be developed, which will have diverse applications in novel medical imaging techniques and detection of concealed nuclear materials. Colossal LAr TPCs are the future for long-baseline-neutrino-oscillation physics around which the international neutrino community is rallying, with the common goal of discovering new physics beyond the Standard Model, which holds the key to our understanding of phenomena such as dark matter and the matter-antimatter asymmetry. I have successfully provided a first demonstration of photographic capturing of muon tracks and single gammas interacting in the Liverpool 40 l LAr TPC using a CCD camera and THGEM. I propose an ambitious project of extensive research to mature this innovative LAr optical readout technology. I will construct a 650 l LAr TPC with integrated CCD/THGEM readout, capable of containing sufficient tracking information for full development and characterisation of this novel detector, with the goal of realising this game-changing technology in the planned future giant LAr TPCs. Camera readout can replace the current charge readout technology and associated scalability complications, and the excellent energy thresholds will enhance detector performance as well as extend research avenues to lower energy fundamental physics. Also, I will explore the Compton imaging capability of LAr CCD/THGEM technology; the superiority of the energy threshold and spatial resolution of this system can offer significant advancement to medical imaging and the detection of concealed nuclear materials.

1 837 911 €

Start date: 2016-03-01, End date: 2021-02-28

I propose a programme of precision tests of the Standard Model of particle physics to be carried out using the LHCb experiment at CERN. The proposal is focussed on studies of CP violation - differences between the behaviour of particles and antiparticles that are fundamental to understanding why the Universe we see today is made up of matter, not antimatter. The innovative feature of this research is the use of Dalitz plot analyses to improve the sensitivity to interesting CP violation effects. Recently I have developed a number of new methods to search for CP violation based on this technique. These methods can be used at LHCb and will extend the physics reach of the experiment beyond what was previously considered possible. I propose to create a small research team, based at the University of Warwick, to develop these methods and to make a number of precise measurements of CP violation parameters using the LHCb experiment. By comparing the results with the Standard Model predictions for these parameters, effects due to non-standard particles can be observed or highly constrained. The results of this work have the potential to redefine the direction of this research field. They will be essential to develop theories of particle physics that go beyond the Standard Model and attempt to address great unanswered questions, such as the origin of the matter--antimatter asymmetry of the Universe.

1 682 800 €

Start date: 2010-02-01, End date: 2016-01-31

The world of our daily experiences, described by classical physics, is built out of fundamental particles, governed by the laws of quantum mechanics. The striking difference between quantum and classical behaviour becomes most apparent in the realm of chaos, an extreme sensitivity to initial conditions, which is common in classical systems but impossible under quantum laws. The investigation of characteristic features of quantum systems whose classical counterparts are chaotic has illuminated foundational problems and led to a variety of technological applications. Traditional quantum theory focuses on the description of closed systems without losses. Every realistic system, however, contains unwanted losses and dissipation, but the idea to engineer them to generate desirable effects has recently come into the focus of scientific attention. The surprising properties of quantum systems with balanced gain and loss (PT-symmetric systems) have sparked much interest. The first experiments on PT-symmetry in optics have been identified as one of the top ten physics discoveries of the past decade in Nature Physics. New experimental areas are rapidly emerging. Our understanding of PT-symmetric quantum systems, however, is still limited. One major shortcoming is that the emergence of chaos and universality in these systems is hitherto nearly unexplored. I propose to investigate PT-symmetric quantum chaos to establish this new research area and overturn some common perceptions in the existing fields of PT-symmetry and quantum chaos. Ultimately this will lead to new experimental applications and quantum technologies. Building on recent conceptual breakthroughs I have made, I will a) identify spectral and dynamical features of chaos in PT-symmetric quantum systems, b) establish new universality classes, c) provide powerful semiclassical tools for the simulation of generic quantum systems, and d) facilitate experimental applications in microwave cavities and cold atoms.

1 293 023 €

Start date: 2018-02-01, End date: 2023-01-31