Center for Theoretical Physics of the Universe (CTPU)

Migdal Effect in Dark Matter Direct Detection Experiments

by Dr Masahiro Ibe (ICRR of Tokyo University)

CTPU Seminar Room (KAIST Munji Campus)

CTPU Seminar Room

KAIST Munji Campus

The elastic scattering of an atomic nucleus plays a central role in the dark matter direct detection experiments. The recoil signatures are detected through ionization, scintillation, and the production of heat in the detectors. In those experiments, it is usually assumed that the atomic electrons around the nucleus immediately follow the motion of the recoiled nucleus. However, it takes some time for the electrons to catch up, which results in ionizations and excitations of the atom. In previous studies, the final state ionizations/excitations are treated separately fr! om the nuclear recoil and are estimated by using the so-called Migdal's approach. In this talk, we discuss our new reformulation of the "atomic recoil" cross section, where we make the energy-momentum conservation and the probability conservation transparent. We also discuss how the final state ionizations/excitations affect the dark matter direct detection experiments.