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Title: Possible evidence for the stochastic acceleration of secondary antiprotons by supernova remnants

In this paper, 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 ~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. The Johns Hopkins Univ., Baltimore, MD (United States)
  2. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)
  3. The Ohio State Univ., Columbus, OH (United States)
Publication Date:
Report Number(s):
FERMILAB-PUB-17-010-A; arXiv:1701.04406
Journal ID: ISSN 2470-0010; PRVDAQ; 1509337
Grant/Contract Number:
AC02-07CH11359; FG02-13ER41958; SC0009924
Type:
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 95; Journal Issue: 12; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1345609
Alternate Identifier(s):
OSTI ID: 1363982