Mineral Detection of Cosmic-Ray Boosted Dark Matter

TL;DR

This paper explores how paleo detectors can detect cosmic-ray boosted dark matter by analyzing nuclear-recoil tracks, significantly improving sensitivity to sub-GeV dark matter interactions compared to current experiments.

Contribution

It introduces the first dedicated analysis of cosmic-ray boosted dark matter in paleo detectors, demonstrating their enhanced sensitivity to sub-GeV dark matter.

Findings

Paleo detectors can detect nuclear-recoil tracks from CRDM with larger lengths than neutrino backgrounds.

Sensitivity to DM-proton scattering cross section improves by 10-100 times over XENONnT.

Paleo detectors are promising for probing sub-GeV dark matter interactions.

Abstract

We present the first dedicated analysis of cosmic-ray boosted dark matter (CRDM) in paleo detectors. Owing to their large kinetic energies, CRDM particles generate nuclear-recoil tracks that extend to substantially larger lengths than those produced by dominant backgrounds from neutrinos and intrinsic radioactivity. Combined with the ultra-large effective geological exposure of $\mathcal{O}(10^{5})~\mathrm{t\,yr}$, paleo detectors provide a uniquely sensitive probe of sub-GeV DM. Considering both constant and vector-mediator interactions, we find that paleo detectors improve the sensitivity to the DM--proton scattering cross section by one to two orders of magnitude compared with the latest XENONnT limits.