Inert extension of the Zee-Babu model

We propose a two-loop induced Zee-Babu-type neutrino mass model at the TeV scale. Although there is no dark matter candidate in the original Zee-Babu model, our model can include the dark matter by introducing an unbroken discrete Z sub(2) symmetry. The discrepancy between the experimental value of the muon anomalous magnetic moment (muon g - 2) and its prediction in the standard model can be explained by contributions from additional vectorlike charged leptons which are necessary to give nonzero neutrino masses. The mass of vectorlike leptons to be slightly above 300 GeV is favored and allowed from the muon g - 2 and the current LHC data. We find that from the structure of the neutrino mass matrix, doubly charged scalar bosons in our model can mainly decay into the same-sign and same-flavor dilepton plus missing transverse momentum. By measuring an excess of these events at the LHC, our model can be distinguished from the other models including doubly charged scalar bosons.