Primordial black holes and lepton flavor violation with scotogenic dark matter

Abstract

Abstract We show that if the lepton flavor-violating μ → eγ process is observed in the MEG II experiment, the initial density of primordial black holes (PBHs) can be constrained with scotogenic dark matter. As a benchmark case, if PBH evaporation occurs in the radiation-dominated era, the initial density may be 2 × 10−17 ≲ β ≲ 3 × 10−16 for the $\mathcal {O}$(TeV)-scale dark sector in the scotogenic model, where β is the ratio of the PBH density ρPBH to the radiation density ρrad at the time of PBH formation. As another benchmark case, if PBHs evaporate in the PBH-dominated era, the initial density may be 1 × 10−8 ≲ β ≲ 3 × 10−7 for $\mathcal {O}$(GeV)-scale dark matter, with other $\mathcal {O}$(TeV)-scale particles in the scotogenic model.