First Search for the Absorption of Fermionic Dark Matter with the PandaX-4T Experiment

Abstract

Compared with the signature of dark matter elastic scattering off nuclei, the absorption of fermionic dark matter by nuclei opens up a new searching channel for light dark matter with a characteristic monoenergetic signal. In this Letter, we explore the 95.0-day data from the PandaX-4T commissioning run and report the first dedicated searching results of the fermionic dark matter absorption signal through a neutral current process. No significant signal was found, and the lowest limit on the dark matter-nucleon interaction cross section is set to be 1.5×10-50 cm2 for a fermionic dark matter mass of 40 MeV/c2 with 90% confidence level.