AMS-02 antiprotons' consistency with a secondary astrophysical origin

The Alpha Magnetic Spectrometer (AMS-02) experiment has ushered cosmic-ray physics into precision era. In an earlier paper [Génolini et al., Phys. Rev. D 99, 123028 (2019)], we designed an improved method to calibrate propagation models on the boron-to-carbon ratio data. Here we provide a robust prediction of the $\overline{p}$ flux, accounting for several sources of uncertainties and their correlations. Combined with a correlation matrix for the $\overline{p}$ data, we show that the latter are consistent with a secondary origin. This paper presents key elements relevant to the dark matter search in this channel, notably by pointing out the inherent difficulties in achieving predictions at the percent-level precision.

Figure 1

AMS-02 errors for $\overline{p}$ data. Statistical (Stat.) and total systematic (Tot. syst.) lines correspond to the errors provided in Ref. [76]. Individual contributions in the systematic errors, namely rigidity cutoff (Cutoff), selection (Sel.), template fitting (Templ.), cross sections (XS), unfolding (Unf.), rigidity scale (Scale), and acceptance (Acc.), built from information provided in Ref. [32] are shown (coloured lines) before (thin) and after (thick) the rescaling applied to match the total systematic error.

Figure 2

Comparison of $\overline{p}$ model and data (a), along with residuals and 68% total confidence interval for the model (gray) together with the transport (blue), the parents (red), and the cross section (green) contributions (b). The residuals of the eigenvectors of the total covariance matrix as a function of the pseudorigidity $\tilde{R}$, as well as their distribution are shown in panel (c) and in the inset.