New Strong Bounds on sub-GeV Dark Matter from Boosted and Migdal Effects

TL;DR

This paper derives new bounds on sub-GeV dark matter by analyzing boosted and Migdal effects, showing that considering momentum transfer significantly improves existing detection limits.

Contribution

It introduces a detailed analysis of the momentum-transfer effect in DM-nucleus scattering, leading to stronger bounds on light dark matter detection.

Findings

Momentum transfer effect is sizable and enhances detection sensitivity.

Existing bounds on DM-nucleus cross section can be significantly improved.

Boosted and Migdal effects provide complementary detection avenues.

Abstract

Due to the low nuclear recoils, sub-GeV dark matter (DM) is usually beyond the sensitivity of the conventional DM direct detection experiments. The boosted and Migdal scattering mechanisms have been proposed as two new complementary avenues to search for light DM. In this work, we consider the momentum-transfer effect in the DM-nucleus scattering to derive the new bounds on sub-GeV DM for these two scenarios. We show that such an effect is sizable so that the existing bounds on the DM-nucleus scattering cross section can be improved significantly.