High energy positrons and the WMAP haze from exciting dark matter

We consider the signals of positrons and electrons from "exciting" dark matter annihilation. Because of the light (m1GeV) force carrier into which the dark matter states can annihilate, the electrons and positrons are generally very boosted, yielding a hard spectrum, in addition to the low energy positrons needed for INTEGRAL observations of the Galactic center. We consider the relevance of this scenario for HEAT, PAMELA, and the WMAP "haze," focusing on light (m 2mπ) bosons, and find that significant signals can be found for all three, although significant signals generally require high dark matter densities. We find that measurements of the positron fraction are generally insensitive to the halo model, but do suffer significant astrophysical uncertainties. We discuss the implications for upcoming PAMELA results.