AMS-02 antiprotons, at last! Secondary astrophysical component and immediate implications for Dark Matter

TL;DR

This paper reevaluates the secondary astrophysical antiproton to proton ratio using AMS-02 data, finds no clear excess suggesting dark matter signals, but notes a potential change in cosmic ray diffusion behavior and sets new constraints on dark matter contributions.

Contribution

It provides an updated analysis of antiproton data with improved flux measurements, assessing the implications for dark matter and cosmic ray propagation models.

Findings

No clear evidence for dark matter-induced antiprotons

Emerging preference for a flatter diffusion coefficient energy dependence

Stricter constraints on dark matter annihilation or decay

Abstract

Using the updated proton and helium fluxes just released by the AMS-02 experiment we reevaluate the secondary astrophysical antiproton to proton ratio and its uncertainties, and compare it with the ratio preliminarly reported by AMS-02. We find no unambiguous evidence for a significant excess with respect to expectations. Yet, some preference for a flatter energy dependence of the diffusion coefficient starts to emerge. Also, we provide a first assessment of the room left for exotic components such as Galactic Dark Matter annihilation or decay, deriving new stringent constraints.