Few remarks on the Higgs boson decays in gauge-Higgs unification

TL;DR

This paper investigates Higgs boson decays within gauge-Higgs unification, analyzing whether the vanishing of Kaluza-Klein mode contributions in certain decays is a general feature or specific to a model, using operator analysis.

Contribution

It demonstrates that no relevant operators respecting SU(3) gauge symmetry exist to produce non-zero Kaluza-Klein contributions to Higgs decays, suggesting the vanishing is a general feature.

Findings

Kaluza-Klein contributions to H→Zγ decay vanish at one-loop in minimal SU(3) models.

Operator analysis shows no relevant operators induce these contributions.

Potential contributions to H→γγ decay from light quark Kaluza-Klein modes are discussed.

Abstract

In the scenario of gauge-Higgs unification, the origin of the Higgs boson is higher dimensional gauge boson. Reflecting its origin, very characteristic predictions are made of the Higgs boson interactions in this scenario. Especially, a remarkable claim has been made: the contribution of non-zero Kaluza-Klein modes to the Higgs decay $H \to Z \gamma$ exactly vanishes in the minimal SU(3) electro-weak unified model, at least at the one-loop level. In this brief report, in order to see whether this prediction is a general feature of the scenario or the consequence of the specific choice of the model, matter content or the order of perturbative expansion, we perform an operator analysis. We demonstrate that there does not exist any relevant operator, respecting the gauge symmetry SU(3) in the bulk. We also comment on the possibly important contribution to the photonic decay $H \to \gamma \gamma$ due to the non-zero Kaluza-Klein modes of light quarks.