Gauge-Higgs Unification in Orbifold Models

TL;DR

This paper explores six-dimensional orbifold models where the Higgs field arises from gauge fields, classifying possible constructions and analyzing their implications for Higgs mass predictions and electroweak stability.

Contribution

It classifies all T^2/Z_N orbifold models with SU(3) symmetry and identifies conditions for stable electroweak symmetry breaking with predictive Higgs mass.

Findings

Models with one Higgs doublet predict m_H=2 m_W.

Certain localized operators do not destabilize the electroweak scale.

A framework for realistic, predictive electroweak models is proposed.

Abstract

Six-dimensional orbifold models where the Higgs field is identified with some internal component of a gauge field are considered. We classify all possible T^2/Z_N orbifold constructions based on a SU(3) electroweak gauge symmetry. Depending on the orbifold twist, models with two, one or zero Higgs doublets can be obtained. Models with one Higgs doublet are particularly interesting because they lead to a prediction for the Higgs mass, which is twice the W boson mass at leading order: m_H=2 m_W. The electroweak scale is quadratically sensitive to the cut-off, but only through very specific localized operators. We study in detail the structure of these operators at one loop, and identify a class of models where they do not destabilize the electroweak scale at the leading order. This provides a very promising framework to construct realistic and predictive models of electroweak symmetry breaking.