Particle Physics Consolidated Grant 2015

Particle physics seeks to understand the Universe, its birth, evolution and fate in terms of the interplay of elementary particles (the quarks and leptons) the fundamental forces (the strong, electromagnetic, and weak forces and gravity) and the force-particles that mediate them (photons, W/Z, gluons and gravitons) and the recently discovered Higgs particle that gives the elementary particles mass. The last thirty years have seen the development of a successful theoretical framework, the Standard Model, in which almost all particle-physics data can be explained. However, the model is incomplete. While it explains what we encounter on Earth, studies of the cosmos indicate the presence of mysterious dark matter that holds galaxies together and even more mysterious dark energy that is driving galaxies apart at an ever-increasing rate. There are so many mysteries! There has never been a better time to be a particle physicist. Oxford's research will advance significantly our understanding of whatever "new-physics" theory will emerge to replace the Standard Model, and will guide the theoretical work to develop it. The Large Hadron Collider (LHC) is about to restart; it reproduces the conditions within a million millionth of a second of the Big Bang. Oxford plays a major role in both ATLAS and LHCb. These experiments have the potential to completely revolutionise our understanding of the universe. In ATLAS, Oxford physicists participated in the exciting discovery of the "Higgs particle", which makes matter matter by giving it mass. We are also searching for particles having "supersymmetry" (SUSY), a theory that would provide a solution to the "dark-matter" that makes up about 80% of the matter in the Universe; ATLAS is also searching for hidden extra spatial dimensions. Oxford physicists on LHCb strive for a better understanding of the origin of the matter-antimatter asymmetry in the Universe, by studying subtle differences in the behaviour of quarks and antiquarks - "CP-violation". This asymmetry permits us to exist. Over the next decade, the LHC will upgrade to higher energy and intensity, and so detector improvements are being prepared for both ATLAS and LHCb. The upgraded detectors will take particle physics to an unprecedented level of sensitivity for the nearly inevitable new-physics observations. Throughout our work we are enabling powerful computing resources and analysis tools that are necessary for the extraction of important discoveries from vast volumes of data. We participate in high-precision experiments which are complementary to the large experiments at the LHC. LZ addresses one of the most important questions in particle physics and cosmology; a search for dark matter, a candidate being the lightest SUSY particle. LSST will measure how quickly the expansion of the universe is speeding up due to the mysterious dark energy that represents 75% of all the energy in the universe and acts like anti-gravity pushing galaxies apart. Similarly g-2 will measure a property of a muon (a heavy electron) that is especially sensitive to fleeting quantum fluctuations of new particles, with unprecedented precision which will also complement measurements of CP-violation from the LHCb experiment. Through T2K, SoLid, MicroBooNE and future projects Oxford aims to understand the elusive neutrino, and its "oscillation" from one type to another. The SNO+ experiment will measure other properties of the neutrino, e.g. whether or not it is its own antiparticle. Throughout, Oxford will continue to develop and enhance capabilities in mechanical and electronic design so that we retain the ability to construct the most sophisticated apparatus for our physics objectives. We will retain our world-leading role for scientific excellence and major state-of-the-art detector construction in particle physics for the future. These are exciting times for particle physics, and Oxford is playing a major role.