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

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 ($\ddot{I}‡+A\to \hat{I}½+A$) and DM-nucleus 3$\to$2 scattering ($\ddot{I}‡+\ddot{I}‡+A\to \ddot{I}•+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 $2.5\times 10^{-46}\mathrm{c}{\mathrm{m}}^2$(90\% C.L.) at DM mass of 10 MeV/c${}^2$. For the DM-nucleus 3$\to$2 scattering scenario, limits are extended to DM mass of 5 MeV/c${}^2$ and 14 MeV/c${}^2$ for the massless dark photon and bound DM final state, respectively.

5 pages, 7 figures