# Fermion Mass Hierarchy in Grand Gauge-Higgs Unification

## TL;DR

This paper explores a five-dimensional grand gauge-Higgs unification model based on SU(6), demonstrating how SM fermion masses and electroweak symmetry breaking can be achieved through boundary interactions and bulk field dynamics.

## Contribution

It presents a novel five-dimensional SU(6) gauge theory framework that naturally generates SM fermion masses and induces electroweak symmetry breaking via boundary and bulk field interactions.

## Key findings

- SM fermion masses are reproduced with mild bulk mass tuning.
- Electroweak symmetry breaking is achieved through additional bulk fields.
- Higgs boson mass is computed within the model.

## Abstract

Grand gauge-Higgs unification of five dimensional $SU(6)$ gauge theory on an orbifold $S^1/Z_2$ is discussed. The Standard model (SM) fermions are introduced on one of the boundaries and some massive bulk fields are also introduced so that they couple to the SM fermions through the mass terms on the boundary. Integrating out the bulk fields generates the SM fermion masses with exponentially small bulk mass dependences. The SM fermion masses except for top quark are shown to be reproduced by mild tuning the bulk masses. One-loop Higgs potential is calculated and it is shown that the electroweak symmetry breaking occurs by introducing additional bulk fields. Higgs boson mass is also computed.