Astro 2020 Science White Paper: Cosmic-ray Antinuclei as Messengers for Dark Matter

TL;DR

This white paper discusses how low-energy cosmic-ray antinuclei, such as antideuterons and antihelium, can serve as unique messengers to detect dark matter signals, highlighting upcoming experiments like AMS-02 and GAPS.

Contribution

It reviews the potential of cosmic-ray antinuclei as dark matter probes and outlines the experimental advancements enabling their detection in the next decade.

Findings

AMS-02 will gather extensive data on rare antinuclei.

GAPS will conduct balloon campaigns optimized for low-energy antinuclei detection.

Antinuclei signatures could provide clear evidence of dark matter.

Abstract

The origin of dark matter is a driving question of modern physics. Low-energy antideuterons provide a "smoking gun" signature of dark matter annihilation or decay, essentially free of astrophysical background. Low-energy antiprotons are a vital partner for this analysis, and low-energy antihelium could provide further discovery space for new physics. In the coming decade, AMS-02 will continue accumulating the large statistics and systematic understanding necessary for it to probe rare antinuclei signatures, and GAPS, which is the first experiment optimized specifically for low-energy cosmic antinuclei, will begin several Antarctic balloon campaigns. The connection of cosmic-ray antinuclei and dark matter is reviewed and the outlook in light of experimental progress is presented.