Mass matrix ansatz and lepton flavor violation in the two-Higgs doublet model-III

Abstract

Predictive Higgs-boson--fermion couplings can be obtained when a specific texture for the fermion mass matrices is included in the general two-Higgs doublet model. We derive the form of these couplings in the charged lepton sector using a Hermitian mass matrix ansatz with four-texture zeros. The presence of unconstrained phases in the vertices ${\ensuremath{\varphi}}_{i}{l}_{i}{l}_{j}$ modifies the pattern of flavor-violating Higgs boson interactions. Bounds on the model parameters are obtained from present limits on rare lepton flavor-violating processes, which could be extended further by the search for the decay $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\tau}}\ensuremath{\mu}\ensuremath{\mu}\ensuremath{\mu}$ and $\ensuremath{\mu}\ensuremath{-}e$ conversion at future experiments. The signal from Higgs boson decays ${\ensuremath{\varphi}}_{i}\ensuremath{\rightarrow}\ensuremath{\tau}\ensuremath{\mu}$ could be searched for at the CERN Large Hadron Collider, while $e\ensuremath{-}\ensuremath{\mu}$ transitions could produce a detectable signal at a future $e\ensuremath{\mu}$ collider, through the reaction ${e}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}\ensuremath{\rightarrow}{h}^{0}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}.$