AMS-02 Antiprotons Reloaded

TL;DR

This paper updates the secondary antiproton flux model using new AMS-02 boron to carbon data, improving the fit to observed antiproton fractions and reducing the need for primary sources like dark matter.

Contribution

It introduces an updated secondary antiproton flux model based on recent AMS-02 data, refining previous estimates within the standard diffusion framework.

Findings

Better fit to AMS-02 antiproton data with the new model

Smaller diffusion coefficient slope improves the background estimate

Reduces the necessity to invoke dark matter as primary antiprotons

Abstract

The AMS-02 collaboration has released preliminary data on the antiproton fraction in cosmic rays. The surprisingly hard antiproton spectrum at high rigidity has triggered speculations about a possible primary antiproton component originating from dark matter annihilations. In this note, we employ newly available AMS-02 boron to carbon data to update the secondary antiproton flux within the standard two-zone diffusion model. The new background permits a considerably better fit to the measured antiproton fraction compared to previous estimates. This is mainly a consequence of the smaller slope of the diffusion coefficient favored by the new AMS-02 boron to carbon data.