Multi-component dark matter in the light of new AMS-02 data

Abstract

We study the possible positron/electron excesses within the multi-component leptonically decaying dark matter (DM) scenario by fitting the most recent AMS-02 data on the positron fraction and total [Formula: see text] flux. We show that both the single- and two-component DM models are able to fit the two AMS-02 datasets. However, the single-component DM model favors the [Formula: see text] energy cutoff from the DM decay less than 1 TeV through the [Formula: see text]-channel, which is already well constrained by the diffuse [Formula: see text]-ray spectrum measured by Fermi-LAT. For the two-component case with closing the [Formula: see text]-mode for the heavy DM particle, we find that the new AMS-02 data allows the heavy DM cutoff larger than 1 TeV, providing a good description of the high-energy behavior of the total [Formula: see text] flux and satisfying the diffuse [Formula: see text]-ray constraint.