Lancaster EPP Group Responsive Grant Bid 2022

The aim of the proposed research is to further understand our Universe at its most basic level via the study of elementary particles and their interactions. Gaining further insight into the properties of the basic building blocks of the Universe (elementary particles) and the nature of the fundamental forces which govern the interactions of these particles will permit deep insights into the origin and evolution of the Universe, especially in the first moments after the Big Bang.

The Lancaster Experimental Particle Physics group is involved with a number of experiments at the Large Hadron Collider (LHC) at CERN that are designed to test our understanding of these fundamental particles and forces (the Standard Model) and also undertake searches for new particles and new physics. The group is also involved in experiments that study neutrinos (one specific type of fundamental particle), searches for Dark Matter candidates and detector development.

This proposal focuses on a sub-set of the group's activities within the ATLAS, NA62 and T2K experiments.

Using data accumulated by the ATLAS experiment at the LHC, we will study the nature of the Higgs boson and search for anomalies in the Standard Model via studies of heavy quark decays. Searches for di-Higgs production will allow deeper understanding of its role in the universe, nature and properties, providing important information . Studies of heavy quark decays will investigate lepton flavour universality, i.e. whether the different types of leptons couple to the W boson with equal strength.

Lepton flavour universality is not associated with any known symmetry and its origins are not known. This is therefore a very interesting area of investigation.

The NA62 experiment offers a unique opportunity to explore the precision frontier of the Standard Model (SM) in a complementary and synergistic way to the LHC experiments. NA62 will execute stringent tests of the Standard Model, search for ultra-rare processes and undertake studies of lepton flavour universality. This work will probe our understanding of fundamental particles and their interactions to an unprecedented level.

By developing new selections for particles produced in neutrino interactions at the T2K experiment, improved understanding of neutrino interactions models can be gained. This will lead to improved measurements of neutrino oscillations with the T2K experiment and provide important information for next-generation experiments that are planned to establish the existence of CP violation in the neutrino sector of the Standard Model.

This could have wide reaching implications for the understanding of the matter- antimatter asymmetry of the Universe.