Constraining primordial black holes as dark matter using AMS-02 data

Primordial black holes (PBHs) are the plausible candidates for the cosmological dark matter. Theoretically, PBHs with masses M_ PBH in the range of 4×10^14∼ 10^17 g can emit sub-GeV electrons and positrons through Hawking radiation. Some of these particles could undergo diffusive reacceleration during their propagation in the Milky Way, resulting in acceleration up to the GeV level. This falls within the observation energy range of AMS-02. In this work, we utilize AMS-02 data to constrain the PBH abundance f_ PBH employing the reacceleration mechanism. Our findings reveal that the limit is more stringent than those derived from Voyager 1 for nearly 𝒪(1) at M_ PBH∼10^16 g under the assumption of a monochromatic PBH mass distribution. The constraints are even more robust in a more realistic scenario involving a log-normal mass distribution of PBHs. Moreover, we explore the impact of varying propagation parameters and solar modulation potential within reasonable ranges, and find that such variations have minimal effects on the final results.