J. C. Montero

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

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.

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

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

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

Abstract In this Letter we consider that assuming: (a) that the only left-handed neutral fermions are the active neutrinos, (b) that B − L is a gauge symmetry, and (c) that the L assignment is restricted to the integer numbers, the anomaly cancellation imply that at least three right-handed neutrinos must be added to the minimal representation content of the electroweak standard model. However, two types of models arise: (i) the usual one where each of the three identical right-handed neutrinos has total lepton number L = 1 ; (ii) and the other one in which two of them carry L = 4 while the third one carries L = − 5 .

Neutrino masses through a type II seesaw mechanism at TeV scale

Abstract In this work we show that we can generate neutrino masses through the type II seesaw mechanism working at TeV scale in the context of a 331 model.

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

Abstract We show that in the minimal 3-3-1 model the flavor changing neutral currents (FCNCs) do not impose necessarily strong constraints on the mass of the Z ′ of the model if we also consider the neutral scalar contributions to such processes, like the neutral meson mass differences and their rare semileptonic decays. We first obtain numerical values for all the mixing matrices of the model i.e., the unitary matrices that rotate the leftand right-handed quarks in each charge sector and give the correct mass of all the quarks and the CKM mixing matrix. Then, we find that there is a range of parameters in which the neutral scalar contributions to these processes may interfere with those of the Z ′, implying that this vector boson may be lighter than it has been thought.

Lepton masses from a TeV scale in a 3-3-1 model

In this work, using the fact that in 3-3-1 models the same leptonic bilinear contributes to the masses of both charged leptons and neutrinos, we develop an effective operator mechanism to generate mass for all leptons. The effective operators have dimension five for the case of charged leptons and dimension seven for neutrinos. By adding extra scalar multiplets and imposing the discrete symmetry

Three-Higgs-doublet model with A4 symmetry

{Z}_{9}\ensuremath{\bigotimes}{Z}_{2}

Seesaw tau lepton mass and calculable neutrino masses in a 3-3-1 model

we are able to generate realistic textures for the leptonic mixing matrix. This mechanism requires new physics at the TeV scale.

3–3–1 models at electroweak scale

Abstract We worked out in detail the three-Higgs-doublet extension of the standard model when the A 4 symmetry, which is imposed to solve the flavor problem, is extended to the scalar sector. The three doublets may be related to the fermion mass generation and, in particular, they may be the unique responsible for generating the neutrino masses. If this is the case, the respective VEVs have to be quite smaller than the electroweak scale. The usual hierarchy in the Yukawa couplings is now moved to a hierarchy in the VEVs which may be justified on dynamical grounds. We consider here the mass spectra in the scalar sector in several situations. When the three doublets are those related with neutrino masses some light scalar arise. However, the later fields are safe, from the phenomenological point of view, since they couple mainly to neutrinos.

Soft CP violation in K-meson systems

In this work we show that in a version of the 3-3-1 model proposed by Duong and Ma, in which the introduction of a scalar sextet is avoided by adding a singlet heavy charged lepton, the t lepton gains mass through a seesawlike mechanism. We also show how to generate neutrino masses at the one-loop level, and give the respective Maki-Nakagawa-Sakata mixing matrices for a set of the parameters. We also consider the effect of adding a singlet right-handed neutrino.