Primordial black holes as cosmic accelerators of light dark matter: Novel direct detection constraints

TL;DR

This paper proposes a novel method to detect light dark matter produced by primordial black hole evaporation using terrestrial experiments, analyzing electron recoil signals and setting new constraints based on existing data.

Contribution

It introduces a new detection avenue for light dark matter via PBH evaporation, analyzing recoil signatures, Lorentz structure dependence, and attenuation effects in Earth.

Findings

Placed constraints on light dark matter using XENONnT, LZ, and PandaX-4T data.

Analyzed recoil spectra dependence on Lorentz structure of interactions.

Discussed detection prospects in neutrino detectors like Super-Kamiokande.

Abstract

Current multi-tonne-scale dark matter (DM) detectors are largely incapable of detecting light dark matter from the Galactic halo due to the energy threshold limitations of their recoil measurements. However, primordial black holes (PBHs) can evaporate via Hawking radiation to particles whose energies are set by the black hole temperature. Consequently, weakly interacting light dark matter (or dark radiation) particles produced in this manner can reach the Earth with sufficient flux and kinetic energy above the experimental thresholds. This opens up a novel avenue to probe the light dark sector in terrestrial experiments. In this work, we explore this possibility by considering fermionic DM produced through PBH evaporation and investigating its electron recoil signatures in direct detection experiments. We analyze both energy independent (constant) and energy dependent (scalar and vector mediated) DM-electron interactions, highlighting the strong dependence of the recoil spectra on the underlying Lorentz structure of the interaction. In addition, we also account for the attenuation effects due to the loss of kinetic energy while DM traverses through Earth's crust, which can significantly modify the incoming DM flux. Incorporating these effects carefully, we place constraints on light DM using the electron recoil data from XENONnT, LZ, and PandaX-4T. Finally, we also discuss the detection prospects of such dark matter in current and future generation neutrino detectors, such as Super-Kamiokande and Hyper-Kamiokande.