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

TL;DR

This paper analyzes the AMS-02 antiproton to proton ratio data to constrain dark matter annihilation, finding that the constraints are comparable to gamma-ray observations and identifying potential dark matter signal regions.

Contribution

It provides a detailed calculation of secondary antiprotons considering propagation uncertainties and derives new bounds on dark matter annihilation cross sections from AMS-02 data.

Findings

AMS-02 data constrains dark matter annihilation cross section.

Dark matter mass around 10 TeV with specific cross section favored.

Constraints comparable to Fermi-LAT dwarf galaxy observations.

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 $\left<\sigma v\right>\sim\mathcal{O}(10^{-23})~\cm^3~\sec^{-1}$.