A possible dark matter annihilation signal in the AMS-02 antiproton data

Ming-Yang Cui, Qiang Yuan, Yue-Lin Sming Tsai, Yi-Zhong Fan

Published 2016-10-12Version 1

A new approach has been adopted to probe the dark matter signal using the latest AMS-02 cosmic ray antiproton flux data. Different from previous studies, we do not assume specific propagation, injection, and solar modulation parameters when calculating the antiproton fluxes, but use the results inferred from the B/C ratio and proton data from the recent PAMELA/AMS-02 measurements instead. A joint likelihood method including the likelihood of these background parameters is established within the Bayesian framework. We find that a dark matter signal is favored with a high test statistic value of $\sim 70$. The rest mass of the dark matter particles is $\sim 30-70$ GeV and the velocity-averaged hadronic annihilation cross section is about $(1-6)\times 10^{-26}$ cm$^{3}$s$^{-1}$, in agreement with that needed to account for the Galactic center GeV excess and/or the weak GeV emission from dwarf galaxies Reticulum 2 and Tucana III. Tight constraints on the dark matter annihilation models are also set in a wide mass region.