Diamond-based cryogenic detector for low-mass dark matter search

Despite significant searches for the dark matter (DM) in our universe, there is no unambiguous evidence for the existence of the DM. Current direct search experiments are focused on detecting interactions between the DM particle and the nucleus in terrestrial detectors. A huge effort is ongoing to increase the sensitivity for the low-mass DM, down to the MeV scales. Carbon-based diamond crystals are especially suited for this purpose as they are made of light nuclei. In particular, they have gained interests from the cryogenic detection community for their cryogenic properties. Long electron-hole pair lifetime in the diamond crystal may allow the discrimination of the desired nuclear recoil signatures from the electron recoil background, which would enable a background reduction in the sub-eV region to the unpreceded level. In this talk, we present the test results from a MMC-based cryogenic detector equipped with a diamond absorber and compare with the results from the same setup with a sapphire absorber.