Are there minimal exceptional aGUTs from stable 5D orbifolds?

TL;DR

This paper investigates five-dimensional orbifold models with exceptional gauge groups to determine if minimal asymptotic grand unified theories are feasible, concluding they are not, and suggesting non-minimal models based on E6.

Contribution

It demonstrates the non-existence of minimal asymptotic GUTs in 5D orbifolds with exceptional groups and explores non-minimal E6-based models with specific stabilisation mechanisms.

Findings

No minimal asymptotic GUTs can be constructed from stable 5D orbifolds with exceptional groups.

Non-minimal E6 models can be achieved, one with supersymmetry and another requiring potential modification.

Stability and symmetry breaking mechanisms are crucial for model viability.

Abstract

In analysing five dimensional orbifolds with exceptional gauge groups, we seek to find stable vacua configurations which satisfy the minimal requirements for asymptotic grand unified models. In this respect we show that no minimal asymptotic grand unified theory can be built. Our results point towards non-minimal models based on $E_6$: one featuring supersymmetry, and the other needing a modification of the Coleman-Weinberg potential to stabilise the breaking of $E_6$ to the standard model gauge group.