# A Robust Excess in the Cosmic-Ray Antiproton Spectrum: Implications for Annihilating Dark Matter

## TL;DR

This study confirms a significant excess of cosmic-ray antiprotons around 10-20 GeV, which could be explained by annihilating dark matter particles of about 64-88 GeV, with implications for understanding dark matter and gamma-ray excesses.

## Contribution

The paper thoroughly revisits uncertainties in cosmic-ray propagation and solar modulation, confirming the antiproton excess and its potential link to dark matter annihilation.

## Key findings

- Confirmed a 4.7σ antiproton excess after accounting for uncertainties.
- Identified dark matter particle mass range of 64-88 GeV consistent with the excess.
- The dark matter models also explain the Galactic Center gamma-ray excess.

## Abstract

An excess of $\sim$10-20 GeV cosmic-ray antiprotons has been identified in the spectrum reported by the AMS-02 Collaboration. The systematic uncertainties associated with this signal, however, have made it difficult to interpret these results. In this paper, we revisit the uncertainties associated with the time, charge and energy-dependent effects of solar modulation, the antiproton production cross section, and interstellar cosmic-ray propagation. After accounting for these uncertainties, we confirm the presence of a 4.7$\sigma$ antiproton excess, consistent with that arising from a $m_{\chi} \approx 64-88$ GeV dark matter particle annihilating to $b\bar{b}$ with a cross section of $\sigma v \simeq (0.8-5.2) \times 10^{-26}$ cm$^{3}$/s. If we allow for the stochastic acceleration of secondary antiprotons in supernova remnants, the data continues to favor a similar range of dark matter models ($m_{\chi}\approx 46-94$ GeV, $\sigma v \approx (0.7-3.8)\times 10^{-26}$ cm$^3/$s) with a significance of 3.3$\sigma$. The same range of dark matter models that are favored to explain the antiproton excess can also accommodate the excess of GeV-scale gamma rays observed from the Galactic Center.