Cosmic Ray Excesses from Multi-component Dark Matter Decays

TL;DR

This paper explores multi-component dark matter decay models to explain cosmic ray excesses observed by AMS-02 and Fermi-LAT, showing that such models can fit the data while remaining consistent with gamma-ray constraints.

Contribution

It introduces multi-component dark matter decay models with specific flavor structures that successfully fit cosmic ray excess data and gamma-ray observations.

Findings

Models fit AMS-02 positron fraction data

Models fit Fermi-LAT total electron and positron flux

Models are consistent with diffuse gamma-ray measurements

Abstract

We use multi-component decaying dark matter (DM) scenario to explain the possible cosmic ray excesses in the positron fraction recently confirmed by AMS-02 and the total $e^+ +e^-$ flux observed by Fermi-LAT. In the two-component DM models, we find an interesting variation of the flavor structure along with the cutoff of the heavy DM. For the three-component DM case, we focus on a particular parameter range in which the best fits prefer to open only 2 DM decay channels with a third DM contributing nothing to the electron and positron spectra. We show that all models give the reasonable fits to both the AMS-02 positron fraction and the Fermi-LAT total $e^++e^-$ flux, which are also consistent with the measured diffuse $\gamma$-ray flux by Fermi-LAT.