The Galactic Center Region Gamma Ray Excess from A Supersymmetric Leptophilic Higgs Model

TL;DR

This paper proposes a supersymmetric leptophilic Higgs model that explains the gamma ray excess from the Galactic Center as annihilating dark matter, matching observed relic density and evading collider constraints.

Contribution

It introduces a four-Higgs-doublet extension of the MSSM with a Z2 symmetry to naturally produce leptophilic dark matter capable of explaining the gamma ray excess.

Findings

Model achieves correct dark matter relic density

Avoids collider bounds from Z width and LEP

Explains gamma ray excess with 7-10 GeV dark matter

Abstract

In a recent paper by Hooper and Goodenough, data from the Fermi Gamma Ray Telescope was analyzed and an excess of gamma rays was claimed to be found in the emission spectrum from the Galactic Center Region. Hooper and Goodenough suggest that the claimed excess can be well explained by 7-10 GeV annihilating dark matter with a power law density profile if the dark matter annihilates predominantly to tau pairs. In this paper we present such a dark matter model by extending the MSSM to include four Higgs doublets and one scalar singlet. A Z2 symmetry is imposed that enforces a Yukawa structure so that the up quarks, down quarks, and leptons each receive mass from a distinct doublet. This leads to an enhanced coupling of scalars to leptons and allows the model to naturally achieve the required phenomenology in order to explain the gamma ray excess. Our model yields the correct dark matter thermal relic density and avoids collider bounds from measurements of the Z width as well as direct production at LEP.