Novel Pathways for Beyond Standard Model Physics

Abstract

In the light of discovering the Higgs boson and null results at the LHC, we look for new pathways for Beyond Standard Model Physics, which could accommodate at least one of the Standard Model shortcomings. (i) Unification with Vector like particles. We look for minimal extensions of the Standard Model with Vector like fermions leading to precision perturbative unification of gauge couplings. Constraints from proton decay and Higgs stability are considered. The minimal models require two different incomplete representations (under SU(5)) of fermions. All of them contain coloured vector fermions, which can be probed at LHC. (ii) Neutrino masses from Clockwork and flavour violation. We studied the fermionic clockwork model for Dirac neutrino masses and studied the lepton flavour violation. We generalized the clockwork framework for the presence of Majorana masses and gave general analytical formulae. Phenomenological implications are studied. (iii). Higgs is a composite pseudo-Nambu goldstone boson. We study a concrete 5D realization of a composite Twin Higgs model from the spontaneous breaking of a global SO(8) symmetry to an SO(7) subgroup, and a discrete symmetry additionally protects mass due to the twin mechanism. We study the model where fermions resonances are heavy enough to alleviate the pressure from direct searches and manifest theories with low fine-tuning survive constraints from the Large Hadron Collider.