Radiative Seesaw Mechanism for Charged Leptons

We discuss a mechanism where charged lepton masses are derived from one-loop diagrams mediated by particles in a dark sector including a dark matter candidate. We focus on a scenario where the muon and electron masses are generated at one loop with new ${\cal O}(1)$ Yukawa couplings. The measured muon anomalous magnetic dipole moment, $(g-2)_\mu$, can be explained in this framework. As an important prediction, the muon and electron Yukawa couplings can largely deviate from their standard model predictions, and such deviations can be tested at High-Luminosity LHC and future $e^+e^-$ colliders.