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 4.7 σ antiproton excess, consistent with that arising from a mχ≈64 - 88 GeV dark matter particle annihilating to b b ¯ with a cross section of σ v ≃(0.8 - 5.2 )×10-26 cm3/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 (mχ≈46 - 94 GeV , σ v ≈(0.7 - 3.8 )×10-26 cm3/s ) with a significance of 3.3 σ . 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.
- Publication:
-
Physical Review D
- Pub Date:
- May 2019
- DOI:
- 10.1103/PhysRevD.99.103026
- arXiv:
- arXiv:1903.02549
- Bibcode:
- 2019PhRvD..99j3026C
- Keywords:
-
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- High Energy Physics - Phenomenology
- E-Print:
- 13 pages, 9 figures and one appendix, changes in v2 in agreement with published version, small revisions in text, results and conclusions unchanged