Radion-Higgs Mixing in 2HDMs

TL;DR

This paper investigates the mixing of the radion with Higgs bosons in a two-Higgs-doublet model within a Randall-Sundrum framework, analyzing implications for LHC Higgs data and heavy scalar searches.

Contribution

It introduces a model with radion-Higgs mixing in a 2HDM context and assesses its compatibility with LHC data, proposing new signatures for heavy scalar detection.

Findings

Radion mixes with CP-even scalars in the model.

LHC data constrains the parameter space.

Distinct decay ratios can differentiate radion from heavy Higgs.

Abstract

We study the custodial Randall-Sundrum model with two Higgs doublets localized in the $\TeV $ brane. The scalar potential is CP- conserving and has a softly broken $Z_2$ symmetry. In the presence of a curvature-scalar mixing term $ \xi_{ab} \mathcal{R} \Phi_a^\dagger \Phi_b$ the radion that stabilizes the extra dimension now mixes with the two CP-even neutral scalars $h$ and $H$. A goodness of fit of the LHC data on the properties of the light Higgs is performed on the parameter space of the type-I and type-II models. LHC direct searches for heavy scalars in different decay channels can help distinguish between the radion and a heavy Higgs. The most important signatures involve the ratio of heavy scalar decays into $b$ quark pairs to those into $Z$ pairs, as well as the decay of the scalar (pseudoscalar) into a $Z$ plus a pseudoscalar (scalar).