The Galactic Center Excess from Z3 Scalar Semi-Annihilations

Abstract

We investigate the possibility of the Z3 scalar singlet model explaining the Fermi galactic centre excess. We find a good fit to the measured spectral excess in the region where the dark matter mass is comparable to the Higgs and the Higgs portal coupling $\lambda_{HS}\sim 0.04$. This preferred region is consistent with constraints from vacuum stability and current dark matter experiments, and will be discovered or falsified soon by future dark matter direct detection experiment.