Some aspects A4 flavor symmetry

Abstract

We review pedagogically non-Abelian discrete groups, which play an important role in the particle physics. We show group-theoretical aspects for S3 and A4 concrete groups, such as representations, their tensor products. We explain how to derive, conjugacy classes, characters, representations, and tensor products for these groups (with a finite number).We also present typical flavor models by using A4 group. Breaking patterns of discrete groups and decompositions of multiplets are important for applications of the non-Abelian discrete symmetry. We discuss these breaking patterns of the non-Abelian discrete group, which are a powerful tool for model buildings.