Constraining primordial black holes as dark matter at JUNO

As an attractive candidate for dark matter, the primordial black holes (PBHs) in the mass range (8×1014 ∼ 1016) g could be detected via their Hawking radiation, including neutrinos and antineutrinos of three flavors. In this paper, we investigate the possibility to constrain the PBHs as dark matter by measuring (anti)neutrino signals at the large liquid-scintillator detector of Jiangmen Underground Neutrino Observatory (JUNO). Among six available detection channels, the inverse beta decay νe + p → e+ + n is shown to be most sensitive to the fraction fPBH of PBHs contributing to the dark matter abundance. Given the PBH mass MPBH = 1015g, we find that JUNO will be able to place an upper bound fPBH ≲ 3×10−5, which is 20 times better than the current best limit fPBH ≲ 6×10−4 from Super-Kamiokande. For heavier PBHs with a lower Hawking temperature, the (anti)neutrinos become less energetic, leading to a relatively weaker bound.