Primordial black holes (PBHs) are a compelling candidate for dark matter (DM). There remain significant parameter spaces to be explored despite current astrophysical observations setting strong limits. Utilizing advanced MeV observation instruments, we have statistically established the upper limit of Hawking radiation emitted by PBHs in DM-dense systems, such as galaxy clusters or dwarf galaxies. These results can set a stringent upper limit on the ratio of PBH to DM, expressed as $f_{\mathrm{PBH}}$. Our results highlight the efficacy of MeV observations in DM-dense environments. The constraints on $f_{\mathrm{PBH}}$ for PBHs in the mass range of ${10}^{16}–{10}^{17}\mathrm{g}$ can be improved significantly compared with the current observations.

• Received 12 December 2023
• Accepted 11 January 2024

DOI:https://doi.org/10.1103/PhysRevD.109.043020