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J. C. Montero

Publications and source records attributed to J. C. Montero.

At least 37 records · Page 2Linked to original sources
arXiv2002

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 $Z_9\otimes Z_2$ we are able to generate realistic textures for the leptonic mixing matrix. This mechanism requires new physics at the TeV scale.

hep-ph↗
arXiv2002

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

In a version of the 3-3-1 model proposed by Duong and Ma the introduction of the scalar sextet for giving mass to the charged leptons is avoided by adding a singlet charged lepton. We show that in this case the $τ$ lepton gains mass through a seesaw--like mechanism. Besides we show how to generate neutrino masses at the tree and at the 1-loop level with the respective Maki-Nakagawa-Sakata leptonic mixing matrices.

hep-ph↗
arXiv2002

Lepton masses in a supersymmetric 3-3-1 model

We consider the mass generation for both charginos and neutralinos in a 3-3-1 supersymmetric model. We show that R-parity breaking interactions leave the electron and one of the neutrinos massless at the tree level. However the same interactions induce masses for these particles at the 1-loop level. Unlike the similar situation in the MSSM the masses of the neutralinos are related to the masses of the charginos.

hep-ph↗
arXiv2002

Left-right asymmetries, the weak mixing angle, and new physics

The goal of this article is to outline the advantages of the measurement of left-right asymmetries in lepton-lepton ($l^{-}l^{-}\to l^{-}l^{-}$) scattering for performing precision measurements of $\sin^2 θ_W$ and the discovery of ``new physics''.

hep-ph↗
arXiv2002

Neutrino masses through see-saw 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 see-saw 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.

hep-ph↗
arXiv2001

Neutrinoless double beta decay with and without Majoron-like boson emission in a 3-3-1 model

We consider the contributions to the neutrinoless double beta decays in a $SU(3)_L\otimes U(1)_N$ electroweak model. We show that for a range of the parameters in the model there are diagrams involving vector-vector-scalar and trilinear scalar couplings which can be potentially as contributing as the light massive Majorana neutrino exchange one. We use these contributions to obtain constraints upon some mass scales of the model, like the masses of the new charged vector and scalar bosons. We also consider briefly the decay in which besides the two electrons a Majoron-like boson is emitted.

hep-ph↗
arXiv2001

A supersymmetric 3-3-1 model

We build the complete supersymmetric version of a 3-3-1 gauge model using the superfield formalism. We point out that a discrete symmetry, similar to the R-symmetry in the minimal supersymmetric standard model, is possible to be defined in this model. Hence we have both R-conserving and R-violating possibilities. Analysis of the mass spectrum of the neutral real scalar fields shown that in this model the lightest scalar Higgs has a mass upper limit, and at the tree level it is 124.5 GeV for a given illustrative set of parameters.

hep-ph↗
arXiv2000

MSW effect with flavor changing interactions and the atmospheric neutrino problem

We consider flavor changing effective neutrino interactions in the context of massive neutrinos in the issue of atmospheric neutrinos. Assuming as usual that this is an indication of the oscillation of muon neutrinos into tau neutrinos we show that there is a set of parameters which is consistent with the MSW resonance condition for the typical Earth density and atmospheric neutrino energies. In particular we show that even if the vacuum mixing angle vanishes it is still possible to have a resonance which is compatible with the atmospheric neutrino data. We also briefly consider the case of the solar neutrino problem.

hep-ph↗
arXiv2000

Left-right asymmetries and exotic vector-boson discovery in lepton-lepton colliders

By considering left-right (L-R) asymmetries we study the capabilities of lepton colliders in searching for new exotic vector bosons. Specifically we study the effect of a doubly charged bilepton boson and an extra neutral vector boson appearing in a 3-3-1 model on the L-R asymmetries for the processes $e^-e^-\to e^-e^-$, $μ^-μ^-\toμ^-μ^-$ and $e^-μ^-\to e^-μ^-$ and show that these asymmetries are very sensitive to these new contributions and that they are in fact powerful tools for discovery this sort of vector bosons.

hep-ph↗
arXiv1999

L-R asymmetries and signals for new bosons

Several left-right parity violating asymmetries in lepton-lepton scattering in fixed target and collider experiments are considered as signals for doubly charged vector bosons (bileptons).

hep-ph↗
arXiv1999

Spontaneous breaking of a global symmetry in a 331 model

In a 331 model in which the lepton masses arise from a scalar sextet it is possible to break spontaneously a global symmetry implying in a pseudoscalar majoron-like Goldstone boson. This majoron does not mix with any other scalar fields and for this reason it does not couple, at the tree level, neither to the charged leptons nor to the quarks. Moreover, its interaction with neutrinos is diagonal. We also argue that there is a set of the parameters in which that the model can be consistent with the invisible Z^0-width and that heavy neutrinos can decay sufficiently rapid by majoron emission having a lifetime shorter than the age of the universe.

hep-ph↗
arXiv1998

Scalar resonances in leptophilic multi-Higgs models

We show that the Higgs resonance can be amplified in a 3-3-1 model with a multi-Higgs "leptophilic" scalar sector. This would allow the observation of the Higgs particle in muon colliders even for Higgs masses considerably higher than the ones expected to be seen in the electroweak standard model framework.

hep-ph↗
arXiv1998

Soft superweak CP violation in a 331 model

We show that it is possible to implement soft superweak CP violation in the context of a 331 model with only three triplets. All CP violation effects come from the exchange of singly and doubly charged scalars. We consider the implication of this mechanism in the quark and lepton sectors. In particular it is shown that in this model, as in most of those which incorporate the scalar mediated CP violation, it is possible to have large electric dipole moments for the muon and the tau lepton while keeping small those of the electron and the neutron. The CKM mixing matrix is real up to the two loop level.

hep-ph↗
arXiv1998

Dark matter: the top of the iceberg?

We argue in favor of the existence of the LIPs, the least interacting particles, which would only interact with ordinary matter through gravitational field and could account for (at least) part of the dark matter. The detectability of LIP matter is addressed at the end.

hep-ph↗
arXiv1998

Concerning CP violation in 331 models

We consider the implementation of CP violation in the context of 331 models. In particular we treat a model where only three scalar triplets are needed in order to give all fermions a mass while keeping neutrino massless. In this case all CP violation is provided by the scalar sector.

hep-ph↗