Exotic Dark Matter Search with CDEX-10 Experiment at China's Jinping Underground Laboratory

TL;DR

This paper reports on a search for exotic low-mass dark matter using the CDEX-10 germanium detector, setting new limits on interaction cross sections in the sub-GeV mass range with no significant signals detected.

Contribution

It introduces new search channels for low-mass dark matter and provides the first experimental limits on these models using the CDEX-10 data.

Findings

No significant dark matter signals found.

Set new upper limits on DM-nucleon cross sections.

Extended limits to DM masses as low as 5 MeV/c².

Abstract

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg$\cdot$day data taken from a p-type point contact germanium detector of CDEX-10 experiment at China Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption ($\chi+A\rightarrow \nu+A$) and DM-nucleus 3$\rightarrow$2 scattering ($\chi+\chi+A\rightarrow \phi+A$), have been analyzed with an energy threshold of 160 eVee. No significant signal was found. Thus new limits on the DM-nucleon interaction cross section are set for both models at sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be $\rm 2.5\times 10^{-46} cm^2$(90\% C.L.) at DM mass of 10 MeV/c$^2$. For the DM-nucleus 3$\rightarrow$2 scattering scenario, limits are extended to DM mass of 5 MeV/c$^2$ and 14 MeV/c$^2$ for the massless dark photon and bound DM final state, respectively.