Decaying Dark Matter can explain the electron/positron excesses

TL;DR

Decaying dark matter offers a plausible explanation for the observed electron/positron excesses in cosmic rays, aligning with constraints and suggesting specific testable predictions.

Contribution

This paper proposes that dark matter decay, rather than annihilation, explains cosmic ray excesses and connects it to composite particles with baryon-like asymmetry.

Findings

Decaying dark matter can explain cosmic ray excesses within observational constraints.

A 2 TeV dark matter mass is consistent with observed abundance and excesses.

Testable predictions are made for HESS observations of the Galactic Ridge.

Abstract

PAMELA and ATIC recently reported excesses in e+ e- cosmic rays. Since the interpretation in terms of DM annihilations was found to be not easily compatible with constraints from photon observations, we consider the DM decay hypothesis and find that it can explain the e+ e- excesses compatibly with all constraints, and can be tested by dedicated HESS observations of the Galactic Ridge. ATIC data indicate a DM mass of about 2 TeV: this mass naturally implies the observed DM abundance relative to ordinary matter if DM is a quasi-stable composite particle with a baryon-like matter asymmetry. Technicolor naturally yields these type of candidates.