Exploring the Higgs Portal with 10/fb at the LHC

TL;DR

This paper investigates how new exotic matter interacting via the Higgs portal can alter Higgs boson signals at the LHC, analyzing current data to constrain such models and their effects on Higgs production and decay.

Contribution

It provides a model-independent analysis of Higgs coupling shifts due to new physics and explores scalar multiplet models consistent with current LHC constraints.

Findings

Allowed shifts in Higgs couplings are constrained by current LHC data.

Scalar multiplet models can modify Higgs production and decay patterns.

Current LHC searches limit the parameter space of new scalar states.

Abstract

We consider the impact of new exotic colored and/or charged matter interacting through the Higgs portal on Standard Model Higgs boson searches at the LHC. Such Higgs portal couplings can induce shifts in the effective Higgs-gluon-gluon and Higgs-photon-photon couplings, thus modifying the Higgs production and decay patterns. We consider two possible interpretations of the current LHC Higgs searches based on ~ 5/fb of data at each detector: 1) a Higgs boson in the mass range (124-126) GeV and 2) a `hidden' heavy Higgs boson which is underproduced due to the suppression of its gluon fusion production cross section. We first perform a model independent analysis of the allowed sizes of such shifts in light of the current LHC data. As a class of possible candidates for new physics which gives rise to such shifts, we investigate the effects of new scalar multiplets charged under the Standard Model gauge symmetries. We determine the scalar parameter space that is allowed by current LHC Higgs searches, and compare with complementary LHC searches that are sensitive to the direct production of colored scalar states.