Dark Matter in Leptophilic Higgs Models After the LHC Run-I

TL;DR

This paper explores leptophilic two-Higgs doublet models with fermionic dark matter, analyzing experimental constraints, collider prospects, and the potential to explain gamma-ray excesses, while considering supersymmetric extensions.

Contribution

It provides a comprehensive analysis of leptophilic Higgs models with dark matter, including collider constraints, dark matter detection, and astrophysical signals, within a supersymmetric framework.

Findings

Leptophilic models allow for lighter Higgs bosons than other two-Higgs models.

The models can satisfy direct detection and invisible decay constraints.

They can also account for the Galactic Center gamma-ray excess.

Abstract

We examine the leptophilic two Higgs doublet model with fermionic dark matter, considering the range of experimental constraints on the Higgs sector. The measurements of the 125 GeV Higgs from the LHC Run-I allow us to focus on those remaining processes that may play an important role at colliders. We find that the leptophilic model allows for a much lighter Higgs than in other two-Higgs models, although discovery at the LHC will be difficult. Adding a dark matter sector motivated by supersymmetric extensions of the leptophilic model, we find the existing parameter space can accommodate constraints from direct detection and the invisible widths of the Higgs and $Z$, while also fitting the Galactic Center gamma ray excess reported by analyses of Fermi-LAT data. We also discuss the status of the fully supersymmetric version of such models, which include four Higgs doublets and a natural dark matter candidate.