Spin-dependent and Spin-independent dark matter scattering off electrons with Ge & Xe Detectors

Mukesh Kumar Pandey^1*, Chih-Pan Wu^1,5, Lakhwinder Singh^3,4, Chung-Chun Hsieh¹, Jiunn-Wei Chen¹, Hsin-Chang Chi2², C. P. Liu²

¹Department of Physics, National Taiwan University, Taipei, Taiwan
²Department of Physics, National Dong Hwa University, Shoufeng, Hualien, Taiwan
³Institute of Physics, Academia Sinica, Taipei, Taiwan
⁴Department of Physics, Central University of South Bihar, Gaya, India
⁵Department of Physics, Universit´e de Montr´eal, Montreal, Qu´ebec, Canada

* Presenter:Mukesh Kumar Pandey, email:mkpandey@gmail.com

Spin-dependent (SD) and Spin-independent (SI) dark matter interaction with atomic electron are well motivated problem in the recent year. Purely spin-dependent interactions between DM and SM target are mediated by a pseudoscalar, an axial-vector, or a dipole interaction mediated by a dark vector. Direct searches of DM look for signals as results of DM scattering off normal matter. As the nature of DM and its non-gravitational interactions with normal matter are still unknown, instead of considering a specific, well-motivated method, we are using multi relativistic random-phase approximation (MCRRPA) and Frozen core approximation (FCA) in the present study. Recently, the relativistic random-phase approximation (RRPA) has been applied, with remarkable successes, to photoexcitation and photoionization of closed-shell atoms and ions of high nuclear charge, such as heavy noble gas atoms, where the ground state is well isolated from the excited states. Furthermore, it is desirable from the experimental point of view to determine which process and kinematic region would be best to constrain a certain type of DM interaction with electrons or nucleons. For this purpose, one has to rely on theoretical analysis. In this work, we try to address the above questions using the atom, Germanium, and Xenon—where most calculations can be carried out using nonrelativistic effective field theory. Calculation—and study its scattering with nonrelativistic LDM particles of a MeV to GeV mass range. Also, the energy transferred by the dark matter particle to the target depends on the reduced mass of the system. Therefore, the current sensitivity of direct detection experiments is limited to a few GeV mass of dark matter particles due to their high energy thresholds of detecting nuclear recoils. The sub-GeV dark matter is a less explored region and highly motivated for next-generation experiments. In this work, we are going to present the scattering of light dark matter (LDM) particles with atomic electrons in the context of nonrelativistic effective field theory. We consider both contact and long-range interaction between dark matter and atomic electron. A state-of-the-art many-body methods are used to evaluate the SD and SI atomic ionization cross-sections of LDM-electron scattering. Detail results will be presented at the meeting.

This work was supported by the Ministry of Science and Technology (MOST) of Taiwan.

Keywords: Spin-dependent (SD) and Spin-independent (SI) dark matter, MCRRPA, FCA, Germanium, and Xenon detector, many-body methods