English

Newly-Discovered Anomalies in Galactic Cosmic Rays: Time for Exotic Scenarios?

High Energy Astrophysical Phenomena 2019-04-24 v1

Abstract

Recent observations of galactic cosmic rays (CR) in the 1-500 GeV energy range have revealed striking deviations from what deemed "standard." The anomalies cut across hadronic and leptonic CRs. I discuss findings that challenge physical mechanisms long held responsible for the CR production in galactic supernova remnants (SNR). I also consider some new physics of particle acceleration in SNR shocks that is not part of conventional models but may explain the anomalies. However, a possible 20-30\% excess remains unaccounted for in the e+/e+e^{+}/e^{+} ratio over the range of a few 100 GeV. If not explained by future models, it suggests an additional source of positrons such as a dark matter decay/annihilation or pulsar contribution. Earlier efforts to explain both the e+/ee^{+}/e^{-} and pp/He anomalies with the "standard" models by adjusting the SNR environmental parameters and multiple sources are critically assessed.

Keywords

Cite

@article{arxiv.1703.05772,
  title  = {Newly-Discovered Anomalies in Galactic Cosmic Rays: Time for Exotic Scenarios?},
  author = {Mikhail Malkov},
  journal= {arXiv preprint arXiv:1703.05772},
  year   = {2019}
}

Comments

Cosmic Rays beyond the Standard Model, San Vito, 2016, http://www.crbtsm.eu/, conference paper