Three family unification in higher dimensional models

TL;DR

This paper explores how three families of chiral fermions can be unified in higher-dimensional orbifold models, with implications for fermion mass hierarchies and flavor symmetries.

Contribution

It demonstrates a framework where gauge, Higgs, and matter fields unify in higher dimensions, and analyzes how flavor symmetries influence fermion mass structures.

Findings

Unification of three fermion families in higher-dimensional models.

Bulk flavor symmetries restrict Yukawa interactions and fermion mass hierarchies.

Orbifold compactification breaks flavor symmetries, affecting fermion mass patterns.

Abstract

In orbifold models, gauge, Higgs and the matter fields can be unified in one multiplet from the compactification of higher dimensional supersymmetric gauge theory. We study how three families of chiral fermions can be unified in the gauge multiplet. The bulk gauge interaction includes the Yukawa interactions to generate masses for quarks and leptons after the electroweak symmetry is broken. The bulk Yukawa interaction has global or gauged flavor symmetry originating from the R symmetry or bulk gauge symmetry, and the Yukawa structure is restricted. When the global and gauged flavor symmetries are broken by orbifold compactification, the remaining gauge symmetry which contains the standard model gauge symmetry is restricted. The restrictions from the bulk flavor symmetries can provide explanations of fermion mass hierarchy.