First search for the absorption of fermionic dark matter with the PandaX-4T experiment

TL;DR

This paper reports the first search for fermionic dark matter absorption using PandaX-4T data, setting new upper limits on interaction cross sections for light dark matter particles.

Contribution

It introduces a novel search channel for light fermionic dark matter via absorption signals and provides the first experimental constraints using PandaX-4T data.

Findings

No significant absorption signal detected.

Set the lowest limit on dark matter-nucleon cross section at 1.5×10⁻⁵⁰ cm² for 40 MeV/c² mass.

First dedicated experimental search for fermionic dark matter absorption.

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 $1.5\times10^{-50}$ cm$^2$ for a fermionic dark matter mass of $40$ MeV/$c^2$ with 90\% confidence level.