Enhancement of Higgs to diphoton decay width in non-perturbative Higgs model

TL;DR

This paper explores non-perturbative and extended Higgs sector models to enhance the Higgs to diphoton decay width, proposing mechanisms involving Higgsinos and strong dynamics that could lead to observable effects.

Contribution

It introduces novel models with non-renormalizable terms and instanton effects that can significantly enhance the Higgs to diphoton decay rate in supersymmetric frameworks.

Findings

Non-renormalizable Higgs sector terms can enhance diphoton decay width.

Instanton effects can invert the sign of Higgs-fermion couplings.

Constructive contributions to decay amplitude are achievable in these models.

Abstract

We investigate a possibility if a loop diagram via Higgsino can enhance the Higgs to diphoton decay width in supersymmetric models with an extension of Higgs sector. A model with an additional non-renormalizable term of Higgs fields is firstly analyzed where the higher order term can introduce the Higgs coupling to Higgsinos as well as charged Higgs bosons. We point out that a choice of the Higgs coupling to obtain a significant size of enhancement of diphoton decay width reduces the Higgs mass and/or a size of non-renormalizable term needs to be large and a cutoff scale is around the weak scale. Another model in which the Higgsino mass term is generated by a non-perturbative instanton effect via a strong dynamics in a context of SUSY QCD is also suggested. It is shown that the sign of the Higgs coupling to fermions is opposite from perturbative models due to an operator including bosonic fields in the denominator and a constructive contribution to the diphoton decay amplitude can be easily obtained in this kind of model.