Secondary Antiprotons in Cosmic Rays

TL;DR

This paper models the production and propagation of cosmic ray antiprotons using a 3D code, providing predictions for fluxes near Earth to aid in understanding cosmic ray physics and searching for new physics signals.

Contribution

It introduces detailed 3D propagation modeling of antiprotons and predictions for fluxes under various heliospheric conditions, improving upon previous simpler models.

Findings

Predicted antiproton fluxes match recent high-statistics data.

Model distinguishes between different propagation and modulation scenarios.

Provides a background estimate for exotic particle searches.

Abstract

High energy collisions of cosmic ray (CR) nuclei with interstellar gas are believed to be the mechanism producing the majority of CR antiprotons. The distinguishing spectral shape with a maximum at 2 GeV and a sharp decrease towards lower energies makes antiprotons a unique probe of the models of particle propagation in the Galaxy and modulation in the heliosphere. Besides, accurate calculation of the secondary antiproton flux provides a ``background'' for searches for exotic signals from the annihilation of supersymmetric particles and primordial black hole evaporation. Recently new data with large statistics on the antiproton flux have become available which allow for such tests to be performed. We use our 3D Galactic cosmic ray propagation code GALPROP to calculate interstellar propagation in several models. For our best model we make predictions of proton and antiproton fluxes near the Earth for different modulation levels and polarity using a steady-state drift model for heliospheric modulation.