Systematic uncertainties in the AMS-02 antiproton excess

Cuoco, Alessandro [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, 52056 Aachen, Germany] Heisig, Jan [UCL] Klamt, Lukas [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, 52056 Aachen, Germany] Korsmeier, Michael [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, 52056 Aachen, Germany] Krämer, Michael [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, 52056 Aachen, Germany]

Global fits of cosmic-ray (CR) fluxes measured by AMS-02 provide great potential to search for exotic sources of antimatter such as dark matter (DM). Previous studies of the AMS-02 antiproton data revealed an excess compatible with DM annihilation. In this article we discuss the robustness of this finding studying two sources of systematic uncertainties affecting the result: the production cross sections for secondary antiprotons and possible correlations in the experimental data, so far not provided by AMS-02. While the former has only a mild effect on the significance of the signal (persisting at the 3\sigma-level), correlations in the data potentially have a strong impact. Using data-driven benchmark models for the correlations, their inclusion can greatly improve the constraining power of the data and, furthermore, enhance the significance of the DM signal up to above 5\sigma. The analysis reveals the importance of providing the covariance of the experimental data to fully exploit its potential.