Production of antimatter nuclei in Galactic cosmic rays

TL;DR

This paper improves the calculation of antimatter nuclei production in cosmic rays, crucial for dark matter searches, by updating cross-sections with recent data and refined models, highlighting dominant uncertainties.

Contribution

It provides an improved evaluation of astrophysical antimatter background in cosmic rays using updated cross-sections and nuclear coalescence models, reducing uncertainties in dark matter indirect detection.

Findings

Updated production cross-sections constrained by recent accelerator data

Improved nuclear coalescence model accounts for antineutron-antiproton asymmetry

Cross-section uncertainties dominate over other astrophysical uncertainties

Abstract

Antimatter nuclei in cosmic rays (CRs) are a promising tool for the indirect detection of dark-matter annihilation signatures. However, the search of new-physics signals in CRs relies on our knowledge of the astrophysical antimatter background which, in turns, depends critically on the several fragmentation cross-sections that regulate production and destruction of antiparticles in the interstellar medium. In this work, we have re-evaluated the astrophysical background of CR antiproton, antineutron, and antihelium nuclei in Galactic CRs using improved calculations. The production cross-sections of individual antinucleons are constrained using updated calculations that make use of recent accelerator data. The production of antideuteron and antihelium nuclei is calculated using an improved model of nuclear coalescence that accounts for the asymmetry in antineutron and antiproton production. We discuss the cross-section induced uncertainties and show that they are dominating in comparison with other uncertainties of astrophysical origin.