Cosmic Ray Excesses from Multi-component Dark Matter Decays

Abstract

We use multi-component decaying dark matter (DM) scenario to explain the possible cosmic ray excesses in the positron fraction recently confirmed by AMS-02 and the total $e^{+}+e^{-}$ flux observed by Fermi-LAT. In the two-component DM models, we find an interesting variation of the flavor structure along with the cutoff of the heavy DM. For the three-component DM case, we focus on a particular parameter range in which the best fits prefer to open only 2 DM decay channels with a third DM contributing nothing to the electron and positron spectra. We show that all models give the reasonable fits to both the AMS-02 positron fraction and the Fermi-LAT total $e^{+}+e^{-}$ flux, which are also consistent with the measured diffuse $\gamma$-ray flux by Fermi-LAT.

Comments: 10 pages, 1 figures, submitted to the special issue of Mod. Phys. Lett.A "Indirect Dark Matter Searches"