Methods and Examples in Flavor Model Building
Rachlin, Bradley Lewis
The structure of the Standard Model provides many hints of new physics at energies above the electroweak scale. In particular, the mass hierarchy and mixing patterns between particles of different flavor are suggestive of an associated gauge symmetry. This flavor symmetry is spontaneously broken at a scale far above the electroweak, leaving behind a residual discrete symmetry that is used to predict fermion masses and mixing angles. Spontaneous symmetry breaking and flavor mixing in the Standard Model are discussed in order to contextualize model building efforts in the flavor sector. A general framework for breaking gauged Lie groups to discrete subgroups is then given, including predictions of resulting scalar mass spectra. Finally, a model with a specific discrete symmetry is constructed and used to derive experimentally compatible fermion mass hierarchies and mixing matrices.