Antiprotons from Dark Matter: Current constraints and future sensitivities

TL;DR

This paper evaluates how current and future cosmic ray antiproton measurements constrain dark matter properties, highlighting AMS-02's potential to improve bounds and reconstruct dark matter parameters in case of detection.

Contribution

It provides a systematic analysis of antiproton data constraints on dark matter and assesses AMS-02's future sensitivity and reconstruction capabilities.

Findings

Current PAMELA data constrain dark matter similarly to Fermi gamma-ray bounds.

AMS-02 can improve constraints by nearly an order of magnitude.

AMS-02 may partially determine dark matter mass and cross-section in case of detection.

Abstract

We systematically analyze the impact of current and foreseen cosmic ray antiproton measurements on the properties of Dark Matter (DM). We find that: 1) The current data from PAMELA impose constraints on annihilating and decaying DM which are similar to (or even slightly stronger than) the most stringent bounds coming from Fermi gamma rays, for hadronic channels and with fiducial choices for the astrophysical parameters. 2) The upcoming data from AMS-02 have the power to improve these constraints by slightly less than one order of magnitude and even to probe the thermal relic DM in the range 30-200 GeV, for hadronic channels. However, with wider choices for the astrophysical parameters the uncertainty on the constraints spans between one and two orders of magnitude. We then explore the capabilities of early AMS-02, data to reconstruct the underlying DM properties in the case of a positive detection of a significant excess (attributed to DM annihilations) over the background. For hadronic channels, we find that AMS-02 should be able to somewhat determine the DM mass and the cross-section, but not the specific annihilation channel nor the branching ratios. If other more exotic annihilation channels are allowed, the reconstruction will be more challenging.