Cosmic–ray and gamma–ray constraints on dark matter stability

Abstract

We examine different constraints on dark matter stability from cosmic–ray and gamma–ray observations and their complementarity through higher–order effects. Two–body and three–body decays of dark matter particles into charged leptons and quarks generically induce decays into monochromatic photons at the quantum level, giving rise to distinct signatures. We also present a general model–independent analysis of hadronic constraints in the mass–lifetime parameter space and compare those constraints to current and projected limits on gamma–ray lines. Furthermore, we discuss how the production of monochromatic photons can be enhanced by kinematic effects, potentially giving rise to observable lines in the gamma–ray sky.