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

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 e+ + e− 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 e+/e− energy cutoff from the DM decay less than 1 TeV through the τ-channel, which is already well constrained by the diffuse γ-ray spectrum measured by Fermi-LAT. For the two-component case with closing the τ-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 e+ + e− flux and satisfying the diffuse γ-ray constraint.