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Title: Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

Abstract

The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the $$\bar{p}/p$$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $$\bar{p}/p$$ ratio observed at rigidities above $$\sim$$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]
  1. Johns Hopkins U.
  2. Chicago U., KICP
  3. Ohio State U.
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1345609
Report Number(s):
FERMILAB-PUB-17-010-A; arXiv:1701.04406
1509337
DOE Contract Number:
AC02-07CH11359
Resource Type:
Journal Article
Resource Relation:
Journal Name: TBD
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Cholis, Ilias, Hooper, Dan, and Linden, Tim. Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants. United States: N. p., 2017. Web.
Cholis, Ilias, Hooper, Dan, & Linden, Tim. Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants. United States.
Cholis, Ilias, Hooper, Dan, and Linden, Tim. Mon . "Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants". United States. doi:. https://www.osti.gov/servlets/purl/1345609.
@article{osti_1345609,
title = {Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants},
author = {Cholis, Ilias and Hooper, Dan and Linden, Tim},
abstractNote = {The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the $\bar{p}/p$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $\bar{p}/p$ ratio observed at rigidities above $\sim$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.},
doi = {},
journal = {TBD},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 16 00:00:00 EST 2017},
month = {Mon Jan 16 00:00:00 EST 2017}
}
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