Gauge Symmetry Reduction from the Extra Space $S^1/Z_2$

TL;DR

This paper investigates how gauge symmetry can be reduced through compactification on an orbifold, specifically analyzing the conditions under which symmetry transitions occur, with applications to grand unified theories.

Contribution

It introduces a novel mechanism for gauge symmetry reduction via orbifold compactification, highlighting the role of parity assignments in symmetry transitions.

Findings

Symmetry transition depends on parity assignments of multiplet components.

Application to SU(5) GUT shows possible gauge symmetry reduction.

Discusses phenomenological implications of symmetry breaking.

Abstract

We study a mechanism of symmetry transition upon compactification of a 5-dimensional field theory on $S^1/Z_2$. The transition occurs unless all components in a multiplet of a symmetry group have a common $Z_2$ parity on $S^1/Z_2$. This mechanism is applied to a reduction of SU(5) gauge symmetry in grand unified theory, and phenomenological implications are discussed.