Lepton electric and magnetic dipole moments via lepton flavor violating spin-1 unparticle interactions

The magnetic dipole moment (MDM) and the electric dipole moment (EDM) of leptons are calculated under the assumption of lepton flavor violation (LFV) induced by spin-1 unparticles with both vector and axial-vector couplings to leptons,including a CP-violating phase. The experimental limits on the muon MDM and LFV process such as the decay l_i->i_jl_kl_k are then used to constrain the LFV couplings for particular values of the unparticle operator dimension d_U and the unparticle scale \Lambda_U, assuming that LFV transitions between the tau and muon leptons are dominant. It is found that the current experimental constraints favor a scenario with dominance of the vector couplings over the axial-vector couplings. We also obtain estimates for the EDMs of the electron and the muon, which are well below the current experimental limits.Comment: 14 pages, 8 figure

Lepton flavor changing higgs boson decays in some extensions of the Standard Model

We present our results for the one-loop contributions to the Higgs boson flavor-changing decays h → μτ in two extensions of the Standard Model: the Little Higgs Model with T-parity and the Two Higgs Doublet Model with a fourth generation of fermions. In both cases we find that the respective branching ratio BR(h → μτ) is of order 10−4 – 10−6. In the case of the 4G2HDM, the one-loop radiative correction is of the same order of magnitude as the tree level branching ratio. We find that in both models the branching ratios for the decay modes h → eτ, eμ are even more suppressed

Lepton flavor changing higgs boson decays in a two higgs doublet model with a fourth generation of fermions

We analyze the flavor changing decay h → μt in the framework of a two Higgs doublet model with a fourth generation of fermions (4G2HDM) which couples only to the heavy scalar doublet. We find that the respective branching ratio at one-loop level can reach values as high as 10-4-10-6 for masses of 300 GeV-1 TeV for the heavy leptons in the fourth family and the new heavy Higgs bosons. These radiative corrections are of the same order of magnitude as the tree level prediction of the 4G2HDM