Title: A robust excess in the cosmic-ray antiproton spectrum: Implications for annihilating dark matter

Abstract

An excess of $~ 10–20 GeV$ cosmic-ray antiprotons has been identified in the spectrum reported by the AMS-02 Collaboration. The systematic uncertainties associated with this signal, however, have made it difficult to interpret these results. In this paper, we revisit the uncertainties associated with the time, charge and energy-dependent effects of solar modulation, the antiproton production cross section, and interstellar cosmic-ray propagation. After accounting for these uncertainties, we confirm the presence of a $4.7σ$ antiproton excess, consistent with that arising from a $$m_χ ≈ 64–88 GeV$$ dark matter particle annihilating to $$\bar{bb}$$ with a cross section of $$σv ≃ (0.8–5.2) × 10^{-26} m^3/s$$. If we allow for the stochastic acceleration of secondary antiprotons in supernova remnants, the data continue to favor a similar range of dark matter models $$(m_χ ≈ 46–94 GeV, σv ≈ (0.7–3.8) × 10^{-26} cm^3/s)$$ with a significance of $3.3σ$. The same range of dark matter models that are favored to explain the antiproton excess can also accommodate the excess of GeV-scale gamma rays observed from the Galactic center.

Authors:

Cholis, Ilias  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-3805-6478"
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Linden, Tim  ^[2];

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• Search DOE PAGES for ORCID "0000-0001-9888-0971"
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Hooper, Dan  ^[3]

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• Search DOE PAGES for ORCID "0000-0001-8837-4127"
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+ Show Author Affiliations

1. Oakland Univ., Rochester, MI (United States)
2. The Ohio State Univ., Columbus, OH (United States)
3. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

Publication Date:

2019-05-31

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:

1529338

Alternate Identifier(s):

OSTI ID: 1523690

Report Number(s):

arXiv:1903.02549; FERMILAB-PUB-19-091-A
Journal ID: ISSN 2470-0010; PRVDAQ; 1723895

Grant/Contract Number:  

AC02-07CH11359; FG02-13ER41958; SC0009924

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review D

Additional Journal Information:

Journal Volume: 99; Journal Issue: 10; Journal ID: ISSN 2470-0010

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS