Possible dark matter annihilation signal in the AMS-02 antiproton data

TL;DR

This study analyzes AMS-02 antiproton data to identify potential dark matter signals, suggesting a possible dark matter particle with mass 20-80 GeV and annihilation cross section consistent with other astrophysical observations.

Contribution

It introduces a Bayesian framework that self-consistently incorporates dark matter signals into cosmic ray background modeling without assuming prior background parameters.

Findings

Dark matter signal favored over background-only hypothesis

Dark matter particle mass estimated between 20-80 GeV

Annihilation cross section consistent with Galactic center excess

Abstract

Using the latest AMS-02 cosmic ray antiproton flux data, we search for potential dark matter annihilation signal. The background parameters about the propagation, source injection, and solar modulation are not assumed {\it a priori}, but based on the results inferred from the recent B/C ratio and proton data measurements instead. The possible dark matter signal is incorporated into the model self-consistently under a Bayesian framework. Compared with the astrophysical background only hypothesis, we find that a dark matter signal is favored. The rest mass of the dark matter particles is $\sim 20-80$ GeV and the velocity-averaged hadronic annihilation cross section is about $(0.2-5)\times 10^{-26}$ 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 spheroidal galaxies Reticulum 2 and Tucana III. Tight constraints on the dark matter annihilation models are also set in a wide mass region.