ERC FUNDED PROJECTS

Why the Universe is void of anti-matter is one of the remaining Big Questions in Science.One explanation is provided within the Standard Model by violation of Charge Parity (CP) symmetry, producing differences between the behavior of particles and their anti-particles.CP violation in the neutrino sector could allow a mechanism by which the matter-anti matter asymmetry arose.The objective of this proposal is to enable a step change in our sensitivity to CP violation in the neutrino sector. I have pioneered the concepts and led the deployment of a small prototype using a novel approach which could eventually lead to the construction of a revolutionary Mega-ton scale Water Cherenkov (WC) neutrino detector.The goal of my research program is to demonstrate the feasibility of this approach via the construction of an intermediate sized prototype with an expandable fiducial mass of up to 10-20kt. It will use a low-cost and lightweight structure, filled with purified water and submerged for mechanical strength and cosmic ray shielding in a 60m deep flooded mine pit in the path of Fermilab’s NuMI neutrino beam in N. Minnesota.The European contribution to this experiment will be profound and definitive.Applying the idea of fast timing and good position resolution of small photodetectors, already pioneered in Europe, in place of large-area photodetector, we will revolutionize WC design.The game-changing nature of this philosophy will be demonstrated via the proof of the detector construction and the observation of electron neutrino events form the NuMI beam.The successful completion of this R&D program will demonstrate a factor of up to 100 decrease in cost compared to conventional detectors and the proof that precision neutrino measurements could be made inside a few years rather than the presently needed decades. The project describes a five year program of work amounting to a total funding request of €3.5M, including an extra €1M of equipment funds.

3 500 000 €

Start date: 2016-10-01, End date: 2021-09-30

String theory provides a unified description of particle physics and gravity, within a consistent theory of quantum gravity. The goal of this research is to develop both the phenomenological implications as well as conceptual foundations of string theory and its non-perturbative completions, M- and F-theory. Both, seemingly independent, questions are deeply connected to a mathematical structure, the Higgs bundle, which characterizes supersymmetric vacua of dimensionally reduced gauge theories, and insights into the moduli space of Higgs bundles will result in a fruitful cross-connection between these subjects. For string theory to engage in a meaningful dialog with particle physics, it is paramount to gain a universal understanding of the low energy effective theories that can arise from it. Building on the success of studying F-theory vacua in terms of Higgs bundles, we propose to develop the Higgs bundle approach for M-theory on G2-manifolds, leading to a universal characterization of the low energy physics. Methods developed for Higgs bundles of d = 3 N = 2 theories obtained from M5-branes on three-manifolds will be used in this process. Associated to each Higgs bundle is a local G2 manifold and we propose a way (using new results in geometry) to construct compact G2 spaces associated to these, which manifestly ensure the phenomenological soundness of the compactifications. Higgs bundles have recently also played a key role in studying the compactifications of the M5-brane in M-theory. We propose and develop a new duality between a d = 4 theory on a four-manifold X4 and a d = 2, N = (2,0) supersymmetric gauge theory on a two-sphere S2, obtained by considering the M5-brane theory on X4xS2. The supersymmetric vacua have a characterization in terms of Higgs bundles, which can be studied with tools developed for F- theory Higgs bundles on four-manifolds. Furthermore we propose a concrete approach to derive this duality from first principles.

1 794 562 €

Start date: 2016-09-01, End date: 2021-08-31

I will study a new regime of high-energy temporal optical soliton dynamics in gas and plasma filled large-bore hollow capillaries—something never previously attempted. Soliton dynamics are fundamental to many of the most fascinating and useful nonlinear processes occurring in conventional optical fibres. Currently the peak powers demonstrated are around 100 megawatts, in hollow-core photonic crystal fibres, with energies of tens of microjoules. I aim to achieve terawatt peak power, millijoule energy-scale, soliton dynamics, and thus combine high-field laser science with the physics of solitons. I will transfer energy from millijoule pump solitons in the near-infrared to the vacuum ultraviolet (100 nm to 200 nm, 6 eV to 12 eV), through resonant dispersive-wave emission. The emitted radiation will be coherent, ultrafast, and tunable through control of the filling gas pressure and capillary bore radius. The predicted conversion efficiencies are up to 20%, leading to VUV energies of over 400 microjoules in pulse durations of just 400 attoseconds (a single-cycle), with corresponding terawatt peak power; making this low-cost and table-top VUV source brighter than synchrotron sources. This will have wide impact: the VUV region, poorly served by current sources, is of great importance to many ultrafast spectroscopy techniques because many materials have electronic resonances there. Through soliton self-compression I will also compress 10 femtosecond, millijoule-scale, near-infrared, pump pulses to both single-cycle and even sub-cycle waveforms, achieving sub-femtosecond durations and terawatt peak powers. These will be the shortest isolated optical pulses ever generated in the near-infrared spectral region. I will use them to drive high-energy isolated attosecond pulse generation in the XUV through HHG. Finally, I will combine these VUV and XUV sources, in a single experiment, to perform proof-of-concept attosecond resolved VUV–XUV pump-probe spectroscopy experiments.

1 723 191 €

Start date: 2016-07-01, End date: 2021-06-30

This project will address directly the two most important unanswered questions in particle physics: the Standard Model (SM) hierarchy problem and the nature of dark matter (DM). The SM was recently completed with the discovery of the Higgs boson at the Large Hadron Collider (LHC) in 2012. We know, however, that the SM cannot be the end of the story for fundamental physics, because it suffers from two major flaws: a lack of stability for the mass of the Higgs boson (the hierarchy problem), and a lack of a candidate for the invisible DM particles known to make up most of the matter in the universe. I will address both of these key problems of modern physics by searching at the LHC for new beyond the SM (BSM) partner states for the SM top quark decaying to new DM particles. The greatly increased quantities of data and world-record collision energies generated by the LHC in the next three years will provide an unprecedented opportunity to find such top partners. Confirmation of their existence would solve the hierarchy problem by providing a mechanism for stabilising the mass of the Higgs boson, while first observation of DM at the LHC would revolutionise our understanding of cosmology and provide a key pointer to the physics of the very early universe. Many leading BSM physics models predict the existence of both top partners and DM, and so this interdisciplinary project provides a unique opportunity to take the next major step forward in developing a unified theory of nature. I will focus on top partners which decay to a top quark and a DM particle, with the former decaying purely to jets and the latter escaping the detector unseen. I will use novel kinematic techniques developed by me to identify and characterise this signal in LHC data, and also accurately measure for the first time the dominant SM background process of associated production of top quarks and a Z boson, which is of great theoretical interest in its own right.

1 584 650 €

Start date: 2016-05-01, End date: 2020-04-30