Phenomenology of a Three Higgs Doublet Model with a U(1)xZ2 flavour symmetry

Abstract: We have studied the main features and the phenomenological consistency of a family-nonuniversal Three Higgs Doublet Model (3HDM) with a softly broken U(1)xZ2 family symmetry that enforces the flavour hierarchies in the Standard Model (SM) while implementing a tree-level Flavour Changing Neutral Current (FCNC) suppression in a Branco-Grimus-Lavoura way. Furthermore, the alignment limit is imposed in the scalar sector to enforce the physical scalar spectrum to accommodate a SM-like Higgs boson. To verify the consistency of our model, we have performed numerical analyses to confront experimental data coming from Higgs searches, electroweak precision tests and quark flavour violating processes. We conclude that the model studied in this thesis is capable of suppressing dangerous FCNCs mediated by non-SM scalars. Furthermore, some scalars are found to be relatively light suggesting that the model succeeds in confronting flavour data even in the presence of scalars with masses around 300 GeV. Hence, the 3HDM presented in this thesis opens the door to direct searches for non-SM scalars at future runs of the LHC.