Interpreting the Fermi-LAT gamma ray excess in the simplified framework

TL;DR

This paper investigates whether a Majorana fermion dark matter model with a scalar mediator can explain the Galactic center gamma ray excess, analyzing multiple astrophysical and cosmological observables.

Contribution

It provides a comprehensive analysis of a simplified dark matter model, constraining parameters using diverse observational data and discarding controversial radio observations.

Findings

Preferred dark matter mass in 10-100 GeV range

Mediator mass in 3-1000 GeV range

Weakly correlated couplings to bottom quarks and tau leptons

Abstract

We test the plausibility that a Majorana fermion dark matter candidate with a scalar mediator explains the gamma ray excess from the Galactic center. Assuming that the mediator couples to all third generation fermions we calculate observables for dark matter abundance and scattering on nuclei, gamma, positron, and anti-proton cosmic ray fluxes, radio emission from dark matter annihilation, and the effect of dark matter annihilations on the CMB. After discarding the controversial radio observation the rest of the data prefers a dark matter (mediator) mass in the 10-100 (3-1000) GeV region and weakly correlated couplings to bottom quarks and tau leptons with values of 10^{-3}-1 at the 68\% credibility level.