Implications for dark matter annihilation from the AMS-02 $\bar{p}/p$ ratio

Abstract

The AMS-02 collaboration has just released the cosmic antiproton to proton ratio $\bar{p}/p$ with a high precision up to $\sim 450$ GeV. In this work, we calculate the secondary antiprotons generated by cosmic ray interactions with the interstellar medium taking into account the uncertainties from the cosmic ray propagation. The $\bar{p}/p$ ratio predicted by these processes shows some tension with the AMS-02 data in some regions of propagation parameters, but the excess is not significant. We then try to derive upper bounds on the dark matter annihilation cross section from the $\bar{p}/p$ data or signal regions favored by the data. It is shown that the constraint derived by the AMS-02 data is similar to that from Fermi-LAT observations of dwarf galaxies. The signal region for dark matter is usually required $m_{\chi }\sim O(10)$ TeV and $⟨\sigma v⟩\sim \mathcal{O}(10^{-23}){\text{cm}}^3{\sec }^{-1}$.

Comments: 15 pages, 4 figures, 3 tables