Probing dark matter particles from evaporating primordial black holes via electron scattering in the CDEX-10 experiment

Abstract

Dark matter (DM) is a major constituent of the Universe. However, no definite evidence of DM particles (denoted as “χ”) has been found in DM direct detection (DD) experiments to date. There is a novel concept of detecting χ from evaporating primordial black holes (PBHs). We search for χ emitted from PBHs by investigating their interaction with target electrons. The examined PBH masses range from 1 × 1015 to 7 × 1016 g under the current limits of PBH abundance fPBH. Using 205.4 kg·day data obtained from the CDEX-10 experiment conducted in the China Jinping Underground Laboratory, we exclude the χ-electron (χ-e) elastic-scattering cross section σχ ∼ 5 × 10−29 cm2 for χ with a mass mχ ≲ 0.1 keV from our results. With the higher radiation background but lower energy threshold (160 eV), CDEX-10 fills a part of the gap in the previous work. If (mχ,σχ) can be determined in the future, DD experiments are expected to impose strong constraints on fPBH for large MPBHs. © Science China Press 2024.