Search for boosted keV-MeV light dark matter particles from evaporating primordial black holes at the CDEX-10 experiment

We present novel constraints on boosted light dark matter particles (denoted as "chi") from evaporating primordial black holes (PBHs) using 205.4 kg center dot day data from the China Jinping Underground Laboratory's CDEX-10 p-type point contact germanium detector with a 160 eVee analysis threshold. chi from PBHs with masses ranging from 1 x 1015 g to 7 x 1016 g are searched in this work. In the presence of PBH abundance compatible with present bounds, our result excludes the chi-nucleon elastic-scattering cross section region from 3.4 x 10-32 cm2 to 2.3 x 10-29 cm2 for chi of 1 keV to 24 MeV from PBHs with masses of 5 x 1015 g, as well as from 1.1 x 10-28 cm2 to 7.6 x 10-28 cm2 for chi of 1 keV to 0.6 MeV from PBHs with masses of 7 x 1016 g. If the chi-nucleon elastic-scattering cross section can be determined in the future, the abundance of PBHs may be severely constrained by chi evaporation. With the lower threshold (160 eVee) of the CDEX-10 experiment compared to the previously used experiments, this work allows for a better reach at soft spectra produced by heavier PBHs, which demonstrates the vast potential of such a technical route to pursue chi from larger PBHs with a low threshold.