# Interpretation of the excess of antiparticles within a modified paradigm of galactic cosmic rays

## TL;DR

This paper proposes a modified paradigm for galactic cosmic rays, explaining excess antiparticles through dual source populations and interactions within accelerators, accounting for observed fluxes and spectral features.

## Contribution

It introduces a two-population source model and internal accelerator interactions to explain cosmic ray antiparticle excesses and spectral hardening.

## Key findings

- Explains positron and antiproton fluxes with dual source populations.
- Accounts for spectral hardening of protons and nuclei above 200 GV.
- Suggests a second source population contributes to ultra-high-energy cosmic rays.

## Abstract

We argue that the anomalously high fluxes of positrons and antiprotons found in cosmic rays (CR) can be satisfactorily explained by introducing two additional elements to the current "standard" paradigm of Galactic CRs. First, we propose that the antiparticles are effectively produced in interactions of primary CRs with the surrounding gas not only in the interstellar medium (ISM) but also inside the accelerators. Secondly, we postulate the existence of two source populations injecting CRs into the ISM with different, (1) soft (close to $FI \propto E^{-2.3}$) and (2) hard ($FII \propto E^{-1.8}$ or harder), energy distributions. Assuming that CRs in the 2nd population of accelerators accumulate "grammage" of the order of $1 \ \rm g/cm^2$ before their leakage into ISM, we can explain the energy distributions and absolute fluxes of both positrons and antiprotons, as well as the fluxes of secondary nuclei of the (Li,Be,B) group. The superposition of contributions of two source populations also explains the reported hardening of the spectra of CR protons and nuclei above 200 GV. The 2nd source population accelerating CRs with a rate at the level below 10 percent of the power of the 1st source population, can be responsible for the highest energy protons and nuclei of Galactic CRs up to the "knee" around $10^{15} \ \rm eV$.