Processes τ → lγ, τ → lll with l = e, µ and µ(τ ) → e(µ)γ are evaluated in the framework of a model based on the extended symmetry gauge SU (3) c ⊗ SU (3) L ⊗ U (1) Y with a leptonic sector consistent of five triplets. Lepton flavor violating processes are allowed at tree level in this model through the new Z gauge boson. We obtained bounds for the mixing angles in the leptonic sector of the model, considering the experimental measurements of the processes from the BELLE and the BABAR collaborations.

We analyze the effect of flavor changing neutral currents within 331 models. In particular, we concentrate in the so-called "economical" models, which have a minimal scalar sector. Taking into account the experimental measurements of observables related to neutral K and B meson mixing, we study the resulting bounds for angles and phases in the mixing matrix for the down quark sector, and the mass and mixing parameters related to the new Z ′ gauge boson.

We carry out a general analysis of tree level flavor changing neutral currents in the context of 331 models, considering arbitrary quark and gauge boson mixing matrices. The results are applied to definite textures of quark mass matrices, and differences between various 331 scenarios are pointed out.

In the context of 331 models we analyze the phenomenology of exotic T quarks with electric charge 2/3. We establish bounds for the corresponding masses and mixing angles and study the decay modes T → bW , tZ and qH. It is found that the decays into scalars are strongly dependent on the model parameters, and can be the dominant ones in a scenario with approximate flavor symmetry.