3.55 keV X-ray Line Signal from Excited Dark Matter in Radiative Neutrino Model

Abstract

We study an exciting dark matter scenario in a radiative neutrino model to explain the X-ray line signal at $3.55$ keV recently reported by XMN-Newton X-ray observatory using data of various galaxy clusters and Andromeda galaxy. We show that the required large cross section for the up-scattering process to explain the X-ray line can be obtained via the resonance of the pseudo-scalar. Moreover this model can be compatible with the thermal production of dark matter and the constraint from the direct detection experiment.

Comments: 12 pages, 2 figures, 1 table; version accepted for publication in Physics Letters B