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arXiv · 1703.05772

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

Mikhail Malkov
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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 $e^{+}/e^{+}$ 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 $e^{+}/e^{-}$ and $p$/He anomalies with the "standard" models by adjusting the SNR environmental parameters and multiple sources are critically assessed.

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Mikhail Malkov. 2017-03-16. Newly-Discovered Anomalies in Galactic Cosmic Rays: Time for Exotic Scenarios?. https://doi.org/10.1016/j.nuclphysbps.2018.07.004

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