Revisiting the AMS-02 antiproton excess: The role of correlated errors

Jul 30, 2021
8 pages
Published in:
  • PoS ICRC2021 (2021) 575
Contribution to:
  • Published: 2021
e-Print:

Citations per year

202020212022012
Abstract: (SISSA)
Cosmic-ray antiprotons are a remarkable diagnostic tool for the study of astroparticle physics' processes in our Galaxy. While the bulk of measured antiprotons is consistent with a secondary origin, several studies have found evidence for a subdominant primary component in the AMS-02 data. In this proceedings article, we revisit the excess considering systematic errors that could affect the signal. Of particular importance are unknown correlations in the AMS-02 systematic errors, the dominant of which are associated with the cross sections for cosmic-ray absorption in the detector. We compute their correlations in a careful reevaluation of nuclear scattering data, utilizing the Glauber-Gribov theory to introduce a welcomed redundancy that we explore in a global fit. The inclusion of correlated errors has a dramatic effect on the significance of the signal. In particular, the analysis becomes more sensitive to the diffusion model at low rigidities. For a minimal extension beyond single-power-law diffusion, the global significance drops below 1σ\sigma severely questioning the robustness of the finding.
Note:
  • Contribution to the 37th International Cosmic Ray Conference (ICRC2021)
  • anti-p: cosmic radiation
  • diffusion: model
  • cosmic radiation: absorption
  • nucleus: scattering
  • correlation
  • AMS
  • Glauber
  • galaxy
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