Can we explain AMS-02 antiproton and positron excesses simultaneously by nearby supernovae without pulsars nor dark matter?

TL;DR

This paper proposes that local supernova remnants colliding with dense clouds can simultaneously explain the observed excesses of antiprotons and positrons in cosmic rays without invoking pulsars or dark matter, fitting recent AMS-02 data.

Contribution

It introduces a natural model where nearby supernovae account for both antiproton and positron excesses through $pp$-collisions, aligning with recent observations and previous predictions.

Findings

Antiproton excess extends to higher energies.

Positron and antiproton fluxes match model predictions.

Supernova age estimated at ~10^5 years.

Abstract

We explain the excess of the antiproton fraction recently reported by the AMS-02 experiment by considering collisions between cosmic-ray protons accelerated by a local supernova remnant (SNR) and the surrounding dense cloud. The same "$pp$-collisions" provide the right ratio of daughter particles to fit the observed positron excess simultaneously in the natural model parameters. The supernova happened in relatively lower metalicity than the major cosmic-ray sources. The cutoff energy of electrons marks the supernova age of $\sim 10^{5}$ years, while the antiproton excess may extend to higher energy. Both antiproton and positron fluxes are completely consistent with our predictions in Fujita, Kohri, Yamasaki and Ioka (2009).