Atomic Compton scattering effect on direct dark matter detection

Abstract Atomic Compton scattering effect significantly contributes to low-energy electronic recoils below its k-shell energy for the direct dark matter detection. Searches on ADM models, photon leptophilic models as well conventional WIMPs background understandings are vitally required clarify effect. We employed relativistic impulse approximation (RIA) together with ab initio Multi-Configuration Dirac-Fock (MCDF) theory obtain atomic Germanium (Ge) Silicon (Si) and Xenon (Xe) atoms. Comparisons low momentum transfer regions our calculations Ge Si achieved. In addition, millicharged particles estimated by RIA in ionization Xe have been evaluated. A factor-of-two discrepancy incoherent-scattering factor (a.k.a. function) near 100 eV/c system between calculation latest version of Geant4 (10.07.02) simulation data is observed. Plans experimental verification perspectives detections will be discussed.