Leptophilic Dark Matter and AMS-02 Cosmic-ray Positron Flux

Understand

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 $\tau\tau$ pair, while both $ee$ and $\mu\mu$ final states should be less than $20\%$.
• When gauge boson final states are included, the best branching ratio of needed $\tau\tau$ mode reduces.