Particle phenomenology from M theory inspired models

Abstract

This thesis focuses on low-energy particle phenomenology arising from G2 compactifications of M theory. We construct a supersymmetric SO(10) model that can be naturally realised in this framework. An appropriate discrete symmetry combined with a symmetry breaking Wilson line suppresses the µ-term and dangerous triplet–matter interactions at the compactification scale. Stabilised moduli introduce back the forbidden terms providing the µ-term with the
phenomenologically expected value of O(TeV). In our model triplets are light and regenerated triplet interactions induce proton decay but safely within experimental constraints. In order to
restore gauge unification we introduce extra, light, vector-like matter multiplets that together with the (unstable) lightest supersymmetric particle (LSP) can provide interesting experimen-tal signatures. We also present a mechanism that generates high scale vacuum expectation values (VEV)s for the scalar components of right-handed neutrinos N of the vector-like pair
that further break the gauge symmetry into the Standard Model SU(3)C × SU(2)Y × U(1)Y as well as can induce the correct neutrino masses. The other significant part of the thesis is focused on collider phenomenology of string/M theory inspired models. In particular we study a prospect for electroweakino discovery at a proposed 100 TeV collider with three leptons plus missing transverse energy signature. We design simple but eective signal regions for this case and using simplified detector-level analysis we evaluate discovery reach and exclusion limits. Assuming 3000 fb−1 of integrated luminosity, W-inos could be discovered (excluded) up to 1.1 (1.8) TeV if the spectrum is not compressed.

Date of Award	2018
Original language	English
Awarding Institution	King's College London
Supervisor	Bobby Acharya (Supervisor) & John Ellis (Supervisor)