Posted: Mar 07, 2019 1:10 pm
by newolder
Not yet a 5-sigma observation (4.7-sigma excess quoted) but intriguing report, nevertheless:
A Robust Excess in the Cosmic-Ray Antiproton Spectrum: Implications for Annihilating Dark Matter

Ilias Cholis, Tim Linden, Dan Hooper
(Submitted on 6 Mar 2019)

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 mχ≈64−88 GeV dark matter particle annihilating to bb¯ with a cross section of σv≃(0.8−5.2)×10−26 cm3/s. If we allow for the stochastic acceleration of secondary antiprotons in supernova remnants, the data continues to favor a similar range of dark matter models (mχ≈46−94 GeV, σv≈(0.7−3.8)×10−26 cm3/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.

More @ arXiv source

ETA A reference in ^that work is to a separate analysis on AMS-02 data by a different group. This second group parameterises various fits to the data and the Log(MDM/GeV) values between 1.7 and 1.9-odd work well. These translate to a DM object of mass ~ 50-77 GeV and are in line with the work here. More intrigue I couldn't wish for on a Thursday. :)

Just have to wait for a full analysis and release by the AMS Consortium. Paging Prof. Ting. :coffee: :popcorn: