Evidence of fresh cosmic ray in galactic plane based on DAMPE measurement of B/C and B/O ratios

TL;DR

This paper presents evidence from DAMPE measurements indicating the presence of fresh cosmic rays in the galactic plane, explaining observed spectral hardening and secondary-to-primary ratios through hadronic interactions near cosmic-ray sources.

Contribution

It introduces a model where secondary cosmic rays originate from hadronic interactions of freshly accelerated cosmic rays near sources, explaining recent spectral observations.

Findings

Secondary-to-primary ratios match DAMPE data

Electron and positron spectra are also explained

Supports the presence of fresh cosmic rays in the galactic plane

Abstract

More and more experiments have identified that the energy spectra of both primary and secondary cosmic-rays exhibit a hardening above $\sim 200$ GV. Most recently, the DAMPE experiment has reported a hardening of boron-to-carbon ratio at $200$ GV. These signs call for modifications of the conventional cosmic-ray (CR) picture. In this work, we propose that the plethoric secondary cosmic rays, for example, boron, antiprotons, originate from the hadronic interactions of freshly accelerated cosmic rays with the interstellar gas near the sources. We find that secondary-to-primary ratios, for example, boron-to-carbon, boron-to-oxygen and antiproton-to-proton ratios, could be well described. The measurements of electrons and positrons could also be accounted for.