Sarah Goes Left and Right Looking Beyond the Standard Model and Meets Susy

Abstract

Progress in the search for physics beyond the Standard Model (BSM) proceeds through two main avenues. The frst requires the development of models that address the host of theoretical and experimental deficiencies of the Standard Model (SM). The second avenue requires scrutinising these models against all available data as well as checks for theoretical consistency. Unfortunately there exists a large number of strongly motivated models as well as an absence of any signs illuminating the correct path nature has chosen. With the lack of a clear direction, automated tools provide an effective means to test as many models as possible. <br /> In this thesis we demonstrate how the SARAH framework can be used in this context as well as its adaptability for confronting unexpected hints of new physics, such as the diphoton excess, that have arisen at the Large Hadron Collider (LHC) over the previous years. We then turn to more theoretical constraints namely, studying the stability of the electroweak vacuum in minimal supersymmetric models. Here we studied the impact of previously neglected directions when including non-standard vacuum expectation values. In the second half of this thesis we consider low-scale left-right symmetric models both with and without supersymmetry. In the non-supersymmetric case we consider constraints arising from charged lepton flavour violation. We have significantly improved existing parametrisations allowing for the new Yukawa couplings to be determined as a function of the underlying model parameters. The last scenario we consider is a model based on SO(10) unification at the high-scale. We build a complete model with TeV-scale breaking of the left-right phase studying in detail the phenomenology.