Cosmic-ray antiproton constraints on light dark matter candidates

TL;DR

This paper demonstrates that cosmic-ray antiproton data strongly constrains light dark matter models with significant quark couplings, especially those with S-wave annihilation, challenging some interpretations of direct detection excesses.

Contribution

It provides new constraints on light dark matter candidates from cosmic-ray antiproton observations, excluding many models with hadronic annihilation channels.

Findings

CR antiproton data exclude many light DM models with quark couplings

Most supersymmetric DM candidates are constrained by these limits

S-wave dominated annihilation scenarios are particularly affected

Abstract

Some direct detection experiments have recently collected excess events that could be interpreted as a dark matter (DM) signal, pointing to particles in the $\sim$10 GeV mass range. We show that scenarios in which DM can self-annihilate with significant couplings to quarks are likely excluded by the cosmic-ray (CR) antiproton data, provided the annihilation is S-wave dominated when DM decouples in the early universe. These limits apply to most of supersymmetric candidates, eg in the minimal supersymmetric standard model (MSSM) and in the next-to-MSSM (NMSSM), and more generally to any thermal DM particle with hadronizing annihilation final states.