Semivisible dark photon in a model with vectorlike leptons for the ( g − 2 ) e , μ and W -boson mass anomalies

We propose a model that realizes a semivisible dark photon which can contribute to the anomalous magnetic moment ( g − 2 ) of both electron and muon. In this model, the electron g − 2 is deviated from the Standard Model (SM) prediction by the 1-loop diagrams involving the vectorlike leptons, while that of muon is deviated due to a nonvanishing gauge kinetic mixing with photons. We also argue that the W -boson mass can be deviated from the SM prediction due to the vectorlike lepton loops, so that the value obtained by the CDF II experiment can be explained. Thus, this model simultaneously explains the recent three anomalies in g − 2 of electron and muon as well as the W -boson mass. The constraints on the O ( 1 ) GeV dark photon can be avoided because of the semivisible decay of the dark photon, A ′ → 2 N → 2 ν 2 χ → 2 ν 4 e , where N is a SM singlet vectorlike neutrino and χ is a C P -even Higgs boson of the U ( 1 ) ′ gauge symmetry.