Results on sub-GeV Dark Matter from a 10 eV Threshold CRESST-III Silicon Detector

TL;DR

This paper reports on a highly sensitive cryogenic silicon detector with a 10 eV threshold, setting new limits on sub-GeV dark matter interactions and improving detection sensitivity significantly.

Contribution

The study introduces a cryogenic silicon detector with the lowest energy threshold reported, enhancing sensitivity to light dark matter particles below 160 MeV/c².

Findings

Achieved a nuclear recoil energy resolution of 1.36 eV

Set new limits on dark matter-silicon interactions for masses below 160 MeV/c²

Excluded noise and surface contamination as main sources of low energy excess

Abstract

We present limits on the spin-independent interaction cross section of dark matter particles with silicon nuclei, derived from data taken with a cryogenic calorimeter with 0.35 g target mass operated in the CRESST-III experiment. A baseline nuclear recoil energy resolution of $(1.36\pm 0.05)$ eV$_{\text{nr}}$, currently the lowest reported for macroscopic particle detectors, and a corresponding energy threshold of $(10.0\pm 0.2)$ eV$_{\text{nr}}$ have been achieved, improving the sensitivity to light dark matter particles with masses below 160 MeV/c$^2$ by a factor of up to 20 compared to previous results. We characterize the observed low energy excess, and we exclude noise triggers and radioactive contaminations on the crystal surfaces as dominant contributions.