Leptophilic dark matter confronts AMS-02 cosmic-ray positron flux

Abstract

With the measurement of positron flux published recently by AMS-02 collaboration, we show how the leptophilic dark matter fits the observation. We obtain the percentages of different products of dark matter annihilation that can best describe the flux of high energy positrons observed by AMS. We show that dark matter annihilates predominantly into ττ pair, while both ee and μμ final states should be less than 20%. When gauge boson final states are included, the best branching ratio of needed ττ mode reduces.