Constraints on light dark matter from primordial black hole evaporation at dark matter direct detection experiments

TL;DR

This paper investigates how primordial black hole evaporation produces light dark matter particles detectable at underground experiments, setting new constraints on PBH properties and dark matter interactions.

Contribution

It provides the first comprehensive analysis of galactic and extragalactic light dark matter flux from PBH evaporation using recent direct detection data.

Findings

Constraints on DM-electron and DM-nucleus scattering cross sections.

Limits on the fraction of dark matter composed of PBHs in specific mass ranges.

Extended constraints on PBH masses beyond the fully evaporated regime.

Abstract

Primordial black holes (PBHs) are able to produce light dark matter (DM) particles via Hawking radiation, and yield a flux of boosted DM that can be probed at underground DM direct detection experiments. We analyze both galactic and extragalactic contributions to the differential flux of light DM from PBH evaporation, and then compute the expected event rate from PBH boosted DM scattering off electrons or nuclei after taking into account the attenuation effect. Using recent data from DM direct detection experiments XENONnT, PandaX-4T and LZ, we set constraints on both DM-electron and DM-nucleus scattering cross sections, as well as the fraction of DM composed of PBHs $f_{\rm PBH}$ for $9\times10^{14}-1\times10^{16}\,\mathrm{g}$ PBHs that are not fully evaporated today. We also investigate the spectral evolution induced by Hawking evaporation throughout the evaporation and post-evaporation regimes. The constraints on the PBH mass are then extended into the $1\times10^{13}-6\times10^{14}\,\mathrm{g}$ window for fully evaporated PBHs.