Secluded singlet fermionic dark matter driven by the Fermi gamma-ray excess

TL;DR

This paper explores a secluded singlet fermionic dark matter model that can explain the Fermi gamma-ray excess at the Galactic Center while satisfying various experimental constraints, providing benchmark points for future collider studies.

Contribution

It demonstrates that a specific secluded fermionic dark matter model can fit the gamma-ray excess data and comply with multiple observational constraints, highlighting viable parameter space.

Findings

Good fit to Fermi gamma-ray data achieved.

Model parameters consistent with antiproton, gamma-ray, and Higgs constraints.

Benchmark points identified for future collider investigations.

Abstract

We examine the possibility that the dark matter (DM) interpretation of the GeV scale Fermi gamma-ray excess at the Galactic Center can be realized in a specific framework - secluded singlet fermionic dark matter model with small mixing between the dark and Standard Model sector. Within this framework it is shown that the DM annihilation into bottom-quark pair, Higgs pair, and new scalar pair can give good fits to the Fermi gamma-ray data. Moreover unavoidable constraints from the antiproton ratio by the PAMELA and AMS-02, the gamma-ray emission from the dwarf spheroidal galaxies by the Fermi-LAT, and the Higgs measurements by the LHC are also considered. Then we found our best-fit parameters for the Fermi gamma-ray excess without conflicting other experimental and cosmological constraints if uncertainties on the DM density profile of the Milky Way Galaxy are taken into account. Successfully surviving parameters are benchmark points for future study on the collider signals.