Do Galactic Antiprotons Come from Decaying Dark Matter?

Abstract

It is shown that the antiproton spectrum reported by the AMS02 collaboration can be accounted for by dark matter (DM) decay if the residence time in the Galactic halo is of order 90 Myr. The DM lifetime assumed, $ 5 \cdot 10^{27}$ s for DM particle mass of 3 TeV, is shown to be consistent with the constraints of diffuse gamma ray background. Alternative sources of antiprotons, such as those from compact objects, are shown to be strongly constrained by neutrino astronomy and therefore unlikely candidates.