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Title: Non-abelian dark matter solutions for Galactic gamma-ray excess and Perseus 3.5 keV X-ray line

Journal Article · · Journal of Cosmology and Astroparticle Physics
 [1];  [2]
  1. Department of Physics, National Tsing Hua University, Hsinchu 300, Taiwan (China)
  2. Department of Physics and Astronomy, University College London, London (United Kingdom)

We attempt to explain simultaneously the Galactic center gamma-ray excess and the 3.5 keV X-ray line from the Perseus cluster based on a class of non-abelian SU(2) DM models, in which the dark matter and an excited state comprise a ''dark'' SU(2) doublet. The non-abelian group kinetically mixes with the standard model gauge group via dimensions-5 operators. The dark matter particles annihilate into standard model fermions, followed by fragmentation and bremsstrahlung, and thus producing a continuous spectrum of gamma-rays. On the other hand, the dark matter particles can annihilate into a pair of excited states, each of which decays back into the dark matter particle and an X-ray photon, which has an energy equal to the mass difference between the dark matter and the excited state, which is set to be 3.5 keV. The large hierarchy between the required X-ray and γ-ray annihilation cross-sections can be achieved by a very small kinetic mixing between the SM and dark sector, which effectively suppresses the annihilation into the standard model fermions but not into the excited state.

OSTI ID:
22525819
Journal Information:
Journal of Cosmology and Astroparticle Physics, Vol. 2015, Issue 05; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
Country of Publication:
United States
Language:
English