A variant two-Higgs doublet model with a new Abelian gauge symmetry

Abstract

We consider a two-Higgs doublet model extended with a broken Abelian gauge symmetry under which all Standard Model (SM) quarks, fourth generation fermions and a new SM-singlet scalar boson are charged. Such a setup is shown to be able to accommodate the muon anomalous magnetic dipole moment while being consistent with existing constraints of flavor-violating decays of charged leptons and Z boson. The new scalar boson offers a suitable dark matter candidate that interacts with the SM particles via the Higgs portal and the Z′ boson associated with the new gauge symmetry. The dark matter direct detection bound is found to impose a strong constraint on the new gauge coupling.