# Constraints from a many-body method on spin-independent dark matter scattering off electrons using data from germanium and xenon detectors

## TL;DR

This paper uses advanced many-body atomic physics methods to set new constraints on light dark matter interactions with electrons, based on data from germanium and xenon detectors, emphasizing the importance of atomic structure effects.

## Contribution

It introduces a state-of-the-art many-body approach to accurately calculate atomic ionization cross sections for dark matter-electron scattering, improving constraints on dark matter properties.

## Key findings

- New upper limits on dark matter-electron interaction parameters.
- Atomic structure effects significantly influence scattering calculations.
- Relativistic effects and electron wave functions are crucial for accurate modeling.

## Abstract

Scattering of light dark matter (LDM) particles with atomic electrons is studied in the context of effective field theory. Contact and long-range interactions between dark matter and an electron are both considered. A state-of-the-art many-body method is used to evaluate the spin-independent atomic ionization cross sections of LDM-electron scattering, with an estimated error about 20%. New upper limits are derived on parameter space spanned by LDM mass and effective coupling strengths using data from the CDMSlite, XENON10, XENON100, and XENON1T experiments. Comparison with existing calculations shows the importance of atomic structure. Two aspects particularly important are relativistic effect for inner-shell ionization and final-state free electron wave function which sensitively depends on the underlying atomic approaches.