First results on sub-GeV spin-dependent dark matter interactions with ${}^7$Li

Abstract

In this work, we want to highlight the potential of lithium as a target for spin-dependent dark matter search in cryogenic experiments, with a special focus on the low-mass region of the parameter space. We operated a prototype detector module based on a Li${}_2$MoO${}_4$ target crystal in an above-ground laboratory. Despite the high background environment, the detector sets competitive limits on spin-dependent interactions of dark matter particles with protons and neutrons for masses between 0.8 GeV/c${}^2$ and 1.5 GeV/c${}^2$.