AMS-02 Positron Excess and Indirect Detection of Three-body Decaying Dark Matter

Understand

We consider indirect detection of meta-stable dark matter particles decaying into a stable neutral particle and a pair of standard model fermions.

• Due to the softer energy spectra from the three-body decay, such models could potentially explain the AMS-02 positron excess without being constrained by the Fermi-LAT gamma-ray data and the cosmic ray anti-proton measurements.
• We scrutinize over different final state fermions, paying special attention to handling of the cosmic ray background and including various contributions from cosmic ray propagation with the help of the \textsc{LikeDM} package.
• It is found that primary decays into an electron-positron pair and a stable neutral particle could give rise to the AMS-02 positron excess and, at the same time, stay unscathed against the gamma-ray and anti-proton constraints.