title: Internal bremsstrahlung signature of real scalar dark matter and consistency with thermal relic density.
abstract: A gamma-ray excess from the Galactic center consistent with line emission around 130 GeV was recently found in the Fermi-LAT data. Although the Fermi-LAT Collaboration has not confirmed its significance, such a signal would be a clear signature of dark matter annihilation. Until now, there have been many attempts to explain the excess by dark matter. However, these efforts tend to give too-small cross sections into photons if consistency with the correct thermal relic density of dark matter is required. In this Letter, we consider a simple Yukawa interaction that can be compatible with both aspects and show which parameters are favored.
authors.affiliation: Institute for Particle Physics Phenomenology, University of Durham, Durham DH1 3LE, United Kingdom.
authors.forename: Takashi
authors.initials: T
authors.lastname: Toma