arXiv subjects

William A. Ponce

Publications and source records attributed to William A. Ponce.

At least 37 records · Page 2Linked to original sources

arXiv2010

$SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ models with four families

In the context of the local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$, we look for possible four family models, where all the particles carry ordinary electric charges. Thirteen different anomaly-free fermion structures emerge, out of which only two are realistic. For the simplest physical structure, we calculate the charged and neutral weak currents and the tree-level Fermion masses. We also look for new sources of flavor changing neutral currents in the quark sector, in connection with the upcoming experimental results at the Large Hadron Collider.

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arXiv2009

FCNC in the 3-3-1 model with right-handed neutrinos

Flavor changing neutral currents coming from a new non-universal neutral Gauge-Boson and from the non-unitary quark mixing matrix for the $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ model with right handed neutrinos are studied. By imposing as experimental constraints the measured values of the 3x3 quark mixing matrix, the neutral meson mixing, and the bounds measured values for direct flavor changing neutral current processes, the largest mixing of the known quarks with the exotic ones can be established, with new sources of flavor changing neutral currents being identified. Our main result is that for a $|V_{tb}|$ value smaller than one, large rates of rare top decays such as $t\to cγ$, $t\to cZ$, and $t\to cg$ (where g stands for the gluon field) are obtained; but if $|V_{tb}|\approx 1$ the model can survive present experimental limits only if the mass of the new neutral Gauge Boson becomes larger that 10 TeV.

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arXiv2009

Stability of the Scalar Potential and Symmetry Breaking in the Economical 3-3-1 Model

A detailed study of the criteria for stability of the scalar potential and the proper electroweak symmetry breaking pattern in the economical 3-3-1 model, is presented. For the analysis we use, and improve, a method previously developed to study the scalar potential in the two-Higgs-doublet extension of the standard model. A new theorem related to the stability of the potential is stated. As a consequence of this study, the consistency of the economical 3-3-1 model emerges.

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arXiv2008

Flavor changing neutral currents with a fourth family of quarks

For a model with a fourth family of quarks, new sources of flavor changing neutral currents are identified by confronting the unitary 4x4 quark mixing matrix with the experimental measured values of the familiar 3x3 quark mixing matrix. By imposing as experimental constraints the known bounds for the flavor changing neutral currents, the largest mixing of the known quarks with the fourth family ones is established. The predictions are: a value for |V_{tb}| significantly different from unity, large rates for rare top decays as t->cγand t->cZ, the last one reachable at the Large Hadrion Collider, and large rates for rare strange decays s->dγand s->dg, where g stands for the gluon field.

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arXiv2007

Phenomenology of the $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ model with exotic charged leptons

A phenomenological analysis of the three-family model based on the local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ with exotic charged leptons, is carried out. Instead of using the minimal scalar sector able to break the symmetry in a proper way, we introduce an alternative set of four Higgs scalar triplets, which combined with an anomaly-free discrete symmetry, produce quark and charged lepton mass spectrum without hierarchies in the Yukawa coupling constants. We also embed the structure into a simple group and show some conditions to achieve a low gauge coupling unification, avoiding possible conflict with proton decay bounds. By using experimental results from the CERN-LEP, SLAC linear collider, and atomic parity violation data, we update constraints on several parameters of the model.

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arXiv2007

Can the Majoron be gauged away?

In a recent paper [Phys. Rev. D73, 075005 (2006)], the authors presented the lepton number violation mechanism in the economic version of the 3-3-1 model, without explicit pointing where the pseudo Goldstone Majoron lies. In this comment we clarify this point and show an extended version of the model where the Goldstone Majoron becomes a gauge away would be Majoron.

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arXiv2006

Lepton masses and mixing without Yukawa hierarchies

We investigate the neutrino masses and mixing patten in a version of the $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ model with one extra exotic charged lepton per family as introduced by Ozer. It is shown that an extended scalar sector, together with a discrete $Z_2$ symmetry, is able to reproduce a consistent lepton mass spectrum without a hierarchy in the Yukawa coupling constants, the former as a carefull balance between one universal see-saw and two radiative mechanisms.

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arXiv2006

Systematic study of the SU(3)_c X SU(4)_L X U(1)_X gauge symmetry

We carry a systematic study of possible extensions of the standard model based on the gauge group SU(3)_c X SU(4)_L X U(1)_X. We consider both models with particles with exotic electric charges and models which do not contain exotic electric charges neither in the gauge boson sector nor in the fermion sector. For the first case an infinite number of models can, in principle, be constructed, while the restriction to non-exotic electric charges only allows for eight different anomaly-free models. Four of them are three-family models in the sense that anomalies cancel by an interplay between the three families, and another two are one-family models where anomalies cancel family by family as in the standard model. The remaining two are two-family models.

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arXiv2006

Phenomenology of the SU(3)_c X SU(3)_L X U(1)_X model with right-handed neutrinos

A phenomenological analysis of the three-family local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ with right-handed neutrinos is carried out. Instead of using the minimal scalar sector able to break the symmetry in a proper way, we introduce an alternative set of four Higgs scalar triplets, which combined with an anomaly-free discrete symmetry, produces a quark mass spectrum without hierarchies in the Yukawa coupling contants. We also embed the structure into a simple gauge group and show some conditions to achieve a low energy gauge coupling unification, avoiding possible conflict with proton decay bounds. By using experimental results from the CERN-LEP, SLAC linear collider and atomic parity violation data, we update constraints on several parameters of the model.

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arXiv2005

Study of the SU(3)_c X SU(3)_L X U(1)_X model with the minimal scalar sector

A study of the three-family local gauge group SU(3)_c X SU(3)_L X U(1)_X with right-handed neutrinos is carried out. We use the minimal scalar sector able to break the symmetry in a proper way and produce, at the same time, masses for the fermion fields. We embed the structure into a simple gauge group and, by using experimental results from the CERN LEP, SLAC linear collider and atomic parity violation data, we also constraint relevant parameters for the new neutral and charged currents. We discuss the mass spectrum for the gauge boson sector and for the spin 1/2 particles. With the use of discrete symmetries and the introduction of extra scalar fields, a consistent mass spectrum could be constructed.

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arXiv2005

Dark matter from the scalar sector of 3-3-1 models without exotic electric charges

We show that three SU(2) singlet neutral scalars (two CP-even and one CP-odd) in the spectrum of models based on the gauge symmetry SU(3)_c X SU(3)_L X U(1)_X, which do not contain exotic electric charges, are realistic candidates for thermally generated self-interacting dark matter in the Universe, a type of dark matter that has been recently proposed in order to overcome some difficulties of collisionless cold dark matter models at the galactic scale. These candidates arise without introducing a new mass scale in the model and/or without the need for a discrete symmetry to stabilize them, but at the expense of tuning several combinations of parameters of the scalar potential.

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arXiv2005

Hierarchical radiative masses in a supersymmetric three-family model without Higgsinos

We study the scalar potential and the mass spectrum of the supersymmetric extension of a three-family model based on the local gauge group $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$, with anomalies canceled among the three families in a nontrivial fashion. In this model the slepton multiplets play the role of the Higgs scalars and no Higgsinos are needed, with the consequence that the sneutrino, the selectron and six other sleptons play the role of the Goldstone bosons of the theory. By introducing an Abelian anomaly-free discrete symmetry and aligning the vacuum in a convenient way, we get a consistent mass spectrum for the scalars and for the spin 1/2 quarks and charged leptons, where only the top and charm quarks and the tau lepton acquire tree level masses while the remaining ordinary charged fermions acquire radiative hierarchical masses.

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arXiv2004

SU(3)_c X SU(4)_L X U(1)_x model for three families

An extension of the Standard Model to the local gauge group $SU(3)_c\otimes SU(4)_L\otimes U(1)_X$ as a three-family model is presented. The model does not contain exotic electric charges and we obtain a consistent mass spectrum by introducing an anomaly-free discrete $Z_2$ symmetry. The neutral currents coupled to all neutral vector bosons in the model are studied. By using experimental results from the CERN LEP, SLAC Linear Collider and atomic parity violation we constrain the mixing angle between two of the neutral currents in the model and the mass of the additional neutral gauge bosons to be $-0.0032\leq\sinθ\leq 0.0031$ and $0.67 \hbox{TeV}\leq M_{Z_2} \leq 6.1$ TeV at 95% C.L., respectively.

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arXiv2004

SU(3)_c X SU(4)_L X U(1)_x without exotic electric charges

We present an extension of the Standard Model to the local gauge group $SU(3)_c\otimes SU(4)_L\otimes U(1)_X$ with a family non-universal treatment and anomalies canceled among the three families in a nontrivial fashion. The mass scales, the gauge boson masses, and the masses for the spin 1/2 particles in the model are analyzed. The neutral currents coupled to all neutral vector bosons in the model are studied, and particular values of the parameters are used in order to simplify the mixing between the three neutral currents present in the theory, mixing which is further constrained by experimental results from the CERN LEP, SLAC Linear Collider, and atomic parity violation.

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arXiv2003

Supersymmetric One-family Model without Higgsinos

The Higgs potential and the mass spectrum of the N=1 supersymmetric extension of a recently proposed one-family model based on the local gauge group $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$, which is a subgroup of the electroweak-strong unification group $E_6$, is analyzed. In this model the slepton multiplets play the role of the Higgs scalars and no Higgsinos are needed, with the consequence that the sneutrino, the selectron and six other sleptons play the role of the Goldstone bosons. We show how the $μ$ problem is successfully addressed in the context of this model which also predicts the existence of a light CP-odd scalar.

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arXiv2002

Minimal Scalar Sector of 3-3-1 Models without Exotic Electric Charges

We study the minimal set of Higgs scalars, for models based on the local gauge group $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$ which do not contain particles with exotic electric charges. We show that only two Higgs $SU(3)_L$ triplets are needed in order to properly break the symmetry. The exact tree-level scalar mass matrices resulting from symmetry breaking are calculated at the minimum of the most general scalar potential, and the gauge bosons are obtained, together with their couplings to the physical scalar fields. We show how the scalar sector introduced is enough to produce masses for fermions in a particular model which is an $E_6$ subgroup. By using experimental results we constrain the scale of new physics to be above 1.3 TeV.

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arXiv2002

Systematic Study of 3-3-1 Models

We carry a systematic study of possible models based on the local gauge group SU(3)_c X SU(3)_L X U(1)_X. Old and new models emerge from the analysis.

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arXiv2001

Analysis of SU(3)_c X SU(3)_L X U(1)_X local gauge theory

Six different models, straightforward extensions of the standard model to SU(3)_c X SU(3)_L X U(1)_X, which do not contain particles with exotic electric charges are described. Two of the models are one family and four are three family models. In two of the three family models one of the families transforms different from the others, and in the other two all the three families are different.

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