Inspired by a significance of 2.4σ for the h→μτ decay observed by the CMS experiment at s=8 TeV, we investigate the Higgs lepton-flavor-violating effects in a generic two-Higgs-doublet model (THDM), where the lepton-flavor-changing neutral currents are induced at the tree level and arise from the Yukawa sector. We revisit the constraints for generic THDM by considering theoretical requirements, precision measurements of δρ and oblique parameters S, T, and U, and Higgs measurements. The bounds from Higgs data play the major limits. With parameter values that simultaneously satisfy the Higgs bounds and the CMS excess of the Higgs coupling to μ-τ, we find that the tree-level τ→3μ and the loop-induced τ→μγ decays are consistent with current experimental upper limits; the discrepancy in muon g-2 between experimental results and standard model predictions can be resolved, and an interesting relation between muon g-2 and the branching ratio (BR) for μ→eγ is found. The generic THDM results show that the order of magnitude of the ratio BR(h→eτ)/BR(h→μτ) is smaller than 10-4. Additionally, we also study the rare decay Z→μτ and get BR(Z→μτ)<10-6.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)