Xinran Li (Princeton University) “The energy resolution and the energy deposition processes in noble liquid dark matter detectors”

Noble liquid detectors, especially liquid argon and liquid xenon time projection chambers (TPCs) have been developed and improved during the last decades. They produced the best limits in the search for one of the best motivated dark matter candidates, weakly interacting massive particles (WIPMs), in the O(10)GeV to O(10)TeV mass region. I’ll first talk about the DarkSide-50 low mass analysis which produced the best limit of 5$\times$10^{-42} cm^2 on spin-independent dark matter nuclear scattering cross section for dark matter masses around 3 GeV. The detector energy resolution around the analysis threshold strongly affects the shape of the limit curve in the low mass region. One main contribution to the energy resolution comes from the intrinsic fluctuations during the energy deposition processes, including the quenching processes and the charge recombination, in noble liquids. Extending to different materials, I’ll also mention the scintillation in xenon doped liquid argon, and the recombination in amorphous selenium. The energy resolution can be improved with sensitivity to the quenched heat energy. Superfluid helium 4 detectors have been proposed to probe nuclear recoil dark matter masses as low as O(10)MeV with current technology. The compatibility with phonon sensors permits sensitivity to all energy deposition channels in superfluid helium.