Dark matter annihilation into right-handed neutrinos and the galactic center gamma-ray excess

Abstract

In this paper, we will discuss a specific case that the dark matter particles annihilate into right-handed neutrinos. We calculate the predicted gamma-ray excess from the galactic center and compare our results with the data from the Fermi-LAT. An approximately 10-60 GeV right-handed neutrino with heavier dark matter particle can perfectly explain the observed spectrum. The annihilation cross section $⟨\sigma v⟩$ falls within the range $0.5$-$4\times 10^{-26}{\text{ cm}}^3/\text{s}$, which is roughly compatible with the WIMP annihilation cross section.

Comments: 11 pages, 5 figures