General vacuum stability of orbifold gauge breaking and application to asymptotic grand unification

TL;DR

This paper analyzes the vacuum stability of gauge symmetry breaking in five-dimensional orbifold models and applies the results to identify viable asymptotic grand unification theories, including specific models based on SU(6) and SU(8).

Contribution

It provides a comprehensive classification of parity assignments ensuring stability in orbifold gauge theories and applies these criteria to find viable aGUT models.

Findings

Identified two viable aGUT models: one SU(6) pathway to the Standard Model.

Found an SU(8) model with intermediate Pati-Salam unification.

Classified stable orbifold symmetry breaking patterns.

Abstract

We examine the vacuum stability of gauge symmetry breaking in five dimensions, compactified on the $S_1/(\mathbb{Z}_2 \times \mathbb{Z}'_2)$ orbifold. We consider $SU(N)$, $Sp(N)$, $SO(2N)$ and $SO(2N+1)$ theories in the bulk, and provide an exhaustive classification of possible parity assignments that lead to stable orbifolds and of the corresponding symmetry breaking patterns. We use these results in the search for viable asymptotic grand unification theories (aGUT), testing the stability criteria on models based on $SU(6)$ and $SU(8)$. As a result, we identify two viable aGUTs: a unique $SU(6)$ pathway down to the Standard Model, and one $SU(8)$ model leading to an intermediate Pati-Salam partial unification.