The Cosmic Ray Antiproton Background for AMS-02

TL;DR

This paper refines the prediction of secondary cosmic ray antiproton fluxes by incorporating new experimental data and detailed particle physics considerations, aiding the interpretation of AMS-02 measurements.

Contribution

It introduces an updated calculation of the antiproton source term using recent NA49 data, including hyperon decay and isospin effects, with a comprehensive uncertainty analysis.

Findings

Updated antiproton flux prediction with reduced uncertainties

Inclusion of hyperon decay and isospin effects in source term

Comparison with previous models and Monte Carlo evaluations

Abstract

The AMS-02 experiment is measuring the cosmic ray antiproton flux with high precision. The interpretation of the upcoming data requires a thorough understanding of the secondary antiproton background. In this work, we employ newly available data of the NA49 experiment at CERN, in order to recalculate the antiproton source term arising from cosmic ray spallations on the interstellar matter. We systematically account for the production of antiprotons via hyperon decay and discuss the possible impact of isospin effects on antineutron production. A detailed comparison of our calculation with the existing literature as well as with Monte Carlo based evaluations of the antiproton source term is provided. Our most important result is an updated prediction for the secondary antiproton flux which includes a realistic assessment of the particle physics uncertainties at all energies.