Gamma-ray triangles: A possible signature of asymmetric dark matter in indirect searches
Abstract
We introduce a new type of gamma-ray spectral feature, which we denominate gamma-ray triangle. This spectral feature arises in scenarios where dark matter self-annihilates via a chiral interaction into two Dirac fermions, which subsequently decay in flight into another fermion and a photon. The resulting photon spectrum resembles a sharp triangle and can be readily searched for in the gamma-ray sky. Using data from the Fermi-LAT and H.E.S.S. instruments, we find no evidence for such a spectral feature and, therefore, set strong upper bounds on the corresponding annihilation cross section. A concrete realization of a scenario yielding gamma-ray triangles consists of an asymmetric dark matter model where the dark matter particle carries lepton number. We show explicitly that this class of models can lead to intense gamma-ray spectral features, potentially at the reach of upcoming gamma-ray telescopes, opening a new window to explore asymmetric dark matter through indirect searches.
- Publication:
-
Physical Review D
- Pub Date:
- November 2016
- DOI:
- 10.1103/PhysRevD.94.103003
- arXiv:
- arXiv:1604.01899
- Bibcode:
- 2016PhRvD..94j3003I
- Keywords:
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- High Energy Physics - Phenomenology;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Experiment
- E-Print:
- 11 pages, 6 figures. Published version