A flavour of family symmetries in a family of flavour models

Abstract

The Standard Model of Particle Physics has many (19) free parameters, most of which (13) are related to the masses and mixing angles of the elementary fermions (quarks and leptons). If we include neutrino masses, even 22 of the 28 parameters are related to the fermion mass sector. Although these parameters can in principle be completely random, there seems to be a lot of structure here: highly hierarchical masses for the quarks and charged leptons and very peculiar mixing angles for the neutrinos. We can use family symmetries to explain this structure. In models with family symmetry, there is not only the (gauge) symmetry between the types of particles, but also a symmetry between the different families. In this thesis, we consider several model building applications of family symmetries