Detectors with low thresholds for electron recoil (ER) open a new window to direct searches of sub-GeV dark matter (DM) candidates. These experimental studies need important theory inputs: the DM scattering rates at detectors through some assumed DM-electron interactions. In this talk, I will present the results of our study on DM-atom scattering through DM-electron interactions at leading order in the context of effective field theory. Our atomic many-body approach is properly benchmarked by atomic data involving not only bound but also continuum states, with a conservative 20% error estimate for DM-xenon and DM-germanium scattering with ER above 12 and 80 eV, respectively. Compared with conventional approaches based on non-relativistic, independent-particle frameworks, the importance of relativistic effects and many-body correlation will be highlighted and discussed.
|Reference to paper (DOI or arXiv)