High Energy Positrons From Annihilating Dark Matter

Understand

Recent preliminary results from the PAMELA experiment indicate the presence of an excess of cosmic ray positrons above 10 GeV.

• In this letter, we consider possibility that this signal is the result of dark matter annihilations taking place in the halo of the Milky Way.
• Rather than focusing on a specific particle physics model, we take a phenomenological approach and consider a variety of masses and two-body annihilation modes, including W+W-, ZZ, b bbar, tau+ tau-, mu+ mu-, and e+e.
• We also consider a range of diffusion parameters consistent with current cosmic ray data.