Consolidated Grant

The aim of the Experimental Particle & Astroparticle Physics (EPAP) group is to address some of the
major open questions in our understanding of matter through the study of the nature of fundamental
particles. In particular, we aim to address many of the open questions in the neutrino sector. We
also continue to search for new physics, addressing phenomena including proton decay, ultra-light dark
matter and gravitational waves from astrophyiscal sources.

Through our long-standing involvement in the Japanese programme of experiments: T2K,
Super-Kamiokande and Hyper-Kamiokande, we work on precision neutrino oscillation measurements
combining both beam and atmospheric neutrino samples, aiming to ultimately understand the
contribution of leptonic CP violation towards explaining the matter-antimatter asymmetry of our
universe. To facilitate successful measurements, we are pursuing a detailed understanding of
relevant neutrino interaction cross-sections (in particular electron neutrino cross-sections),
detector response and systematic uncertainties. We also support these efforts by developing the
computing software infrastructure required to analyse the large data volumes and maintaining the
outer detector for Super-Kamiokande.

We also play an important role in the SNO+ experiment in Canada, which will collect its main data
to search for neutrino-less double beta decay, hence probing the nature and mass of the neutrino,
during this grant period. Our work will enable this and other key measurements (such as solar and
reactor neutrino spectra that further probe oscillation parameters) through analysis coordination
and a careful study of time correlated backgrounds and detector response.

Through IceCUBE we access the very high end of the neutrino energy spectrum, preparing and
searching for new physics within, the astrophysical neutrino sample, and placing limits on Lorentz
violation from atmospheric neutrino data.

Another goal of the group is the search for proton-decay, motivated by many unified theories,
combining extensive phenomenological expertise with our experimental experience in Super-K and
Hyper-K. Further new physics will be addressed through the Atomic Interferometer Observatory
Network (AION). Our contributions to the development of this series of UK-based quantum interferometer
detectors to explore ultra-light dark matter candidates and detect gravitational waves from
astrophysical sources, will involve detailed sensitivity studies to inform the design.