Model building using dihedral symmetries

Abstract

The standard model is tremendously successful in describing and predicting the outcome of several particle physics experiments. It provides a way to generate masses of quarks and leptons, but it does not explain the masses’ hierarchy. It also does not explain the hierarchical pattern followed by quark mixings. This is known as the Flavor puzzle. In this thesis, we have constructed a four Higgs doublet model using dihedral symmetry D4 to explain the hierarchy in masses and mixings. We have transformed our fields in such a way that the source of generation of mass for the third generation is di⇥erent from the first two generations, which allows us to dilute the Yukawa coupling hierarchies. We have also connected quark mixings with the dynamics of the scalar sector, suggesting that the fact that the third generation of quarks is much heavier than the first two generations is intimately connected to the smallness of the o⇥-Cabibbo elements.