Loop-induced Higgs decays in two Higgs doublet scenarios: some observations

TL;DR

This paper investigates the decay modes of neutral Higgs bosons into gamma gamma and Z gamma in two Higgs doublet models, analyzing conditions under which Z gamma decay can dominate, considering various theoretical and experimental constraints.

Contribution

It provides a detailed analysis of Higgs decay channels in two Higgs doublet models, highlighting scenarios where Z gamma decay can dominate over gamma gamma, under specific model types and constraints.

Findings

For the 125-GeV Higgs, Z gamma dominance is mostly excluded by constraints.

Other neutral scalars can have Z gamma decay dominate in certain models.

For CP-odd states, Z gamma dominance is limited to Types II and Y models.

Abstract

We study the decay of three neutral Higgs bosons into {\gamma}{\gamma} and Z{\gamma} in the four major types of two Higgs doublet models with CP conserved. Particular focus is made on the possibility of the width of the latter decay dominating over the former. For the 125-GeV scalar, such a possibility is mostly excluded when one imposes all theoretical and experimental constraints, other than the Higgs data at the Large Hadron Collider. For the other CP-even neutral scalar, there remain regions in each kind of model where the Z{\gamma} mode dominates. For the CP-odd state, this possibility is restricted to only the models of Types II and Y, in certain regions of the parameter space.