Enhanced anti-deuteron Dark Matter signal and the implications of PAMELA

Abstract

We show that the jet structure of DM annihilation or decay products enhances the anti-deuterium production rate by orders of magnitude compared to the previous computations done assuming a spherically symmetric coalescence model. In particular, in the limit of heavy DM, M >> m_p, we get a constant rather than 1/M^2 suppressed anti-deuterium production rate. Therefore, a detectable anti-deuterium signal is compatible with the lack of an excess in the anti-proton PAMELA flux. Most importantly, cosmic anti-deuterium searches become sensitive to the annihilations or decays of heavy DM, suggesting to extend the experimental anti-deuterium searches above the O(1) GeV scale.

Comments: 13 pages, 7 figures. Final version