Scrutinizing the evidence for dark matter in cosmic-ray antiprotons

Abstract

Global fits of primary and secondary cosmic-ray (CR) fluxes measured by AMS-02 have great potential to study CR propagation models and search for exotic sources of antimatter such as annihilating dark matter (DM). Previous studies of AMS-02 antiprotons revealed a possible hint for a DM signal which, however, could be affected by systematic uncertainties. To test the robustness of such a DM signal, in this work we systematically study two important sources of uncertainties: the antiproton production cross sections needed to calculate the source spectra of secondary antiprotons and the potential correlations in the experimental data, so far not provided by the AMS-02 Collaboration. To investigate the impact of cross-section uncertainties we perform global fits of CR spectra including a covariance matrix determined from nuclear cross-section measurements. As an alternative approach, we perform a joint fit to both the CR and cross-section data. The two methods agree and show that cross-section uncertainties have a small effect on the CR fits and on the significance of a potential DM signal, which we find to be at the level of $3\sigma$. Correlations in the data can have a much larger impact. To illustrate this effect, we determine possible benchmark models for the correlations in a data-driven method. The inclusion of correlations strongly improves the constraints on the propagation model and, furthermore, enhances the significance of the DM signal up to above $5\sigma$. Our analysis demonstrates the importance of providing the covariance of the experimental data, which is needed to fully exploit their potential.

25 pages,12 figures; v2: Figs. 8 and 12 added, references added, minor improvements in presentation, matches published version

References in corpus (20)

• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• Cosmic-Ray Proton and Helium Spectra from the First CREAM Flight
• A Tale of Tails: Dark Matter Interpretations of the Fermi GeV Excess in Light of Background Model Systematics
• Constraints on WIMP Dark Matter from the High Energy PAMELA $\bar{p}/p$ data
• The galactic antiproton spectrum at high energies: background expectation vs. exotic contributions
• Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center
• Cosmic Ray Antiprotons at High Energies
• What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?
• New calculation of antiproton production by cosmic ray protons and nuclei
• Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis
• Galactic cosmic-ray propagation in the light of AMS-02: I. Analysis of protons, helium, and antiprotons
• Low energy cosmic ray positron fraction explained by charge-sign dependent solar modulation
• The Cosmic Ray Antiproton Background for AMS-02
• A fussy revisitation of antiprotons as a tool for Dark Matter searches
• The Semi-Hooperon: Gamma-ray and anti-proton excesses in the Galactic Center
• Hidden Sector Dark Matter and the Galactic Center Gamma-Ray Excess: A Closer Look
• Can AMS-02 discriminate the origin of an anti-proton signal?
• Dark Matter Annihilation into Four-Body Final States and Implications for the AMS Antiproton Excess
• Antiproton signatures from astrophysical and dark matter sources at the galactic center
• The Fluorescence detector Array of Single-pixel Telescopes: Contributions to the 35th International Cosmic Ray Conference (ICRC 2017)

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