V. Pleitez

SU(3)⊗U(1) model for electroweak interactions

We consider a gauge model based on a SU(3){direct product}U(1) symmetry in which the lepton number is violated explicitly by charged scalar and gauge bosons, including a vector field with double electric charge.

Lepton masses in an SU ( 3 ) L ⊗ U ( 1 ) N gauge model

The

Concerning the Landau pole in 3-3-1 models

SU(3)_c\otimes SU(3)_L\otimes U(1)_N

Global analysis of the post-SNO solar neutrino data for standard and nonstandard oscillation mechanisms

model of Pisano and Pleitez extends the Standard Model in a particularly nice way, so that for example the anomalies cancel only when the number of generations is divisible by three. The original version of the model has some problems accounting for the lepton masses. We resolve this problem by modifying the details of the symmetry breaking sector in the model.

Neutrino masses through the seesaw mechanism in 3-3-1 models

Abstract.Some 3-3-1 models predict the existence of a non-perturbative regime at the TeV scale. We study in these models and their supersymmetric extensions, the energy at which the non-perturbative limit and a Landau-like pole arise. An order of magnitude for the mass of the extra neutral vector boson,

Supersymmetric 3-3-1 model with right-handed neutrinos

Z^\prime

Supersymmetric 3-3-1 model

, present in these models is also obtained.

Gauging U(1) symmetries and the number of right-handed neutrinos

What can we learn from solar neutrino observations? Is there any solution to the solar neutrino anomaly which is favored by the present experimental panorama? After SNO results, is it possible to affirm that neutrinos have mass? In order to answer such questions we analyze the current available data from the solar neutrino experiments, including the recent SNO result, in view of many acceptable solutions to the solar neutrino problem based on different conversion mechanisms, for the first time using the same statistical procedure. This allows us to do a direct comparison of the goodness of the fit among different solutions, from which we can discuss and conclude on the current status of each proposed dynamical mechanism. These solutions are based on different assumptions: ~a! neutrino mass and mixing, ~b! a nonvanishing neutrino magnetic moment, ~c! the existence of nonstandard flavor-changing and nonuniversal neutrino interactions, and ~d! a tiny violation of the equivalence principle. We investigate the quality of the fit provided by each one of these solutions not only to the total rate measured by all the solar neutrino experiments but also to the recoil electron energy spectrum measured at different zenith angles by the Super-Kamiokande Collaboration. We conclude that several nonstandard neutrino flavor conversion mechanisms provide a very good fit to the experimental data which is comparable with ~or even slightly better than! the most famous solution to the solar neutrino anomaly based on the neutrino oscillation induced by mass.

Neutrino masses through a type II seesaw mechanism at TeV scale

Some years ago it was shown by Ma that in the context of the electroweak standard model there are, at the tree level, only three ways to generate small neutrino masses by the seesaw mechanism via one effective dimension-five operator. Here we extend this approach to 3-3-1 chiral models showing that in this case there are several dimension-five operators and we also consider their tree level realization.

Flavor-changing neutral currents in the minimal 3-3-1 model revisited

We consider the supersymmetric extension of the 3-3-1 model with right-handed neutrinos. We study the mass spectra in the scalar and pseudoscalar sectors, and for a given set of the input parameters, we find that the lightest scalar in the model has a mass of 130 GeVand the lightest pseudoscalar has mass of 5 GeV. However, this pseudoscalar decouples from the Z 0 at high energy scales since it is almost a