arXiv subjects

P. V. Dong

Publications and source records attributed to P. V. Dong.

At least 37 records · Page 2Linked to original sources

arXiv2012

Question of Peccei-Quinn symmetry and quark masses in the economical 3-3-1 model

We show that there is an infinite number of U(1) symmetries like Peccei-Quinn symmetry in the 3-3-1 model with minimal scalar sector---two scalar triplets. Moreover, all of them are completely broken due to the model's scalars by themselves (notice that these scalars as known have been often used to break the gauge symmetry and generating the masses for the model's particles). There is no any residual Peccei-Quinn symmetry. Because of the minimal scalar content there are some quarks that are massless at tree-level, but they can get consistent mass contributions at one-loop due to this fact. Interestingly, axions as associated with the mentioned U(1)s breaking (including Majoron due to lepton-charge breaking) are all gauged away because they are also the Goldstone bosons responsible for the gauge symmetry breaking as usual.

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arXiv2011

The S_3 flavor symmetry in 3-3-1 models

We propose two 3-3-1 models (with either neutral fermions or right-handed neutrinos) based on S_3 flavor symmetry responsible for fermion masses and mixings. The models can be distinguished upon the new charge embedding (\mathcal{L}) relevant to lepton number. The neutrino small masses can be given via a cooperation of type I and type II seesaw mechanisms. The latest data on neutrino oscillation can be fitted provided that the flavor symmetry is broken via two different directions S_3 \rightarrow Z_2 and S_3 \rightarrow Z_3 (or equivalently in the sequel S_3 \rightarrow Z_2 \rightarrow Identity), in which the second direction is due to a scalar triplet and another antisextet as small perturbation. In addition, breaking of either lepton parity in the model with neutral fermions or lepton number in the model with right-handed neutrinos must be happened due to the \mathcal{L}-violating scalar potential. The TeV seesaw scale can be naturally recognized in the former model. The degenerate masses of fermion pairs (μ, τ), (c, t) and (s, b) are respectively separated due to the S_3 \rightarrow Z_3 breaking.

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arXiv2011

Neutrino Masses in Supersymmetric Economical SU(3)_C X SU(3)_L X U(1)_X Model

The R-symmetry formalism is applied for the supersymmetric economical SU(3)_C X SU(3)_L X U(1)_X (3-3-1) model. The generalization of the minimal supersymmetric standard model relation among R-parity, spin and matter parity is derived, and discrete symmetries for the proton stability in this model are imposed. We show that in such a case it is able to give leptons masses at just the tree level. A simple mechanism for the mass generation of the neutrinos is explored. With the new R-parity, the neutral fermions get mass matrix with two distinct sectors: one light which is identified with neutrino mass matrix, another heavy one which is identified with neutralinos one. The similar situation exists in the charged fermion sector. Some phenomenological consequences such as proton stability, neutrinoless double beta decays are discussed.

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arXiv2011

Photon-radion conversion cross-sections in external electromagnetic field

An attempt is made to present some experimental predictions of the Randall-Sundrum model, where compactification radius of the extra dimension is stabilized by the radion, which is a scalar field lighter than the graviton Kaluza-Klein states. We calculate the conversion cross-sections of the photons into the radions in the external electromagnetic fields, namely, in the static fields and in a periodic field of the wave guide. Numerical evaluations of the total cross-sections are also given. Our result shows that the conversion cross-section in the static electric field is quite small. But, in the static magnetic and periodic fields, the radion productions are much enhanced.

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arXiv2011

A simple model of gauged lepton and baryon charges

We argue that simpler fermionic contents, responsible for the extension of the standard model with gauged lepton and baryon charges, can be constructed by assuming existence of so-called leptoquarks (j,k) with exotic electric charges q_j=1/2, q_k=-1/2. Some new features in our model are that (i) as the natural consequences of anomaly cancelation the right-handed neutrinos exist, and the number of the observed fermion families is equal to the number of the fundamental colors; (ii) although the lepton and baryon charges are conserved, the neutrinos can obtain small masses through the type I seesaw mechanism in similarity to the standard context, and the baryogenesis can be generated in several cases. They all are natural results due to the spontaneous breaking of these charges. Some constraints on the new physics via flavor changing and related phenomenologies such as the stable scalar with anomalous electric charge and interested processes at colliders are also discussed.

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arXiv2011

A possible minimal gauge-Higgs unification

A possible minimal model of the gauge-Higgs unification based on the higher dimensional spacetime M^4 X (S^1/Z_2) and the bulk gauge symmetry SU(3)_C X SU(3)_W X U(1)_X is constructed in some details. We argue that the Weinberg angle and the electromagnetic current can be correctly identified if one introduces the extra U(1)_X above and a bulk scalar triplet. The VEV of this scalar as well as the orbifold boundary conditions will break the bulk gauge symmetry down to that of the standard model. A new neutral zero-mode gauge boson Z' exists that gains mass via this VEV. We propose a simple fermion content that is free from all the anomalies when the extra brane-localized chiral fermions are taken into account as well. The issues on recovering a standard model chiral-fermion spectrum with the masses and flavor mixing are also discussed, where we need to introduce the two other brane scalars which also contribute to the Z' mass in the similar way as the scalar triplet. The neutrinos can get small masses via a type I seesaw mechanism. In this model, the mass of the Z' boson and the compactification scale are very constrained as respectively given in the ranges: 2.7 TeV < m_Z' < 13.6 TeV and 40 TeV < 1/R < 200 TeV.

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arXiv2010

The 3-3-1 model with S_4 flavor symmetry

We construct a 3-3-1 model based on family symmetry S_4 responsible for the neutrino and quark masses. The tribimaximal neutrino mixing and the diagonal quark mixing have been obtained. The new lepton charge \mathcal{L} related to the ordinary lepton charge L and a SU(3) charge by L=2/\sqrt{3} T_8+\mathcal{L} and the lepton parity P_l=(-)^L known as a residual symmetry of L have been introduced which provide insights in this kind of model. The expected vacuum alignments resulting in potential minimization can origin from appropriate violation terms of S_4 and \mathcal{L}. The smallness of seesaw contributions can be explained from the existence of such terms too. If P_l is not broken by the vacuum values of the scalar fields, there is no mixing between the exotic and the ordinary quarks at the tree level.

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arXiv2010

Symmetry Factors of Feynman Diagrams for Scalar Fields

The symmetry factor of Feynman diagrams for real and complex scalar fields is presented. Being analysis of Wick expansion for Green functions, the mentioned factor is derived in a general form. The symmetry factor can be separated into two ones corresponding to that of connected and vacuum diagrams. The determination of symmetry factors for the vacuum diagrams is necessary as they play a role in the effective action and phase transitions in cosmology. In the complex scalar theory the diagrams different in topology may give the same contribution, hence inverse of the symmetry factor (1/S) for total contribution is a summation of each similar ones (1/S_i), i.e., 1/S = \sum_i (1/S_i).

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arXiv2010

The 3-3-1 model with A_4 flavor symmetry

We argue that the A_4 symmetry as required by three flavors of fermions may well-embed in the SU(3)_C X SU(3)_L X U(1)_X gauge model. The new neutral fermion singlets as introduced in a canonical seesaw mechanism can be combined with the standard model lepton doublets to perform SU(3)_L triplets. Various leptoscalar multiplets such as singlets, doublets, and triplets as played in the models of A_4 are unified in single SU(3)_L antisextets. As a result, naturally light neutrinos with various kinds of mass hierarchies are obtained as a combination of type I and type II seesaw contributions. The observed neutrino mixing pattern in terms of the Harrison-Perkins-Scott proposal is obtained by enforcing of the A_4 group. The quark masses and Cabibbo-Kobayashi-Maskawa mixing matrix are also discussed. By virtue of very heavy antisextets the nature of the vacuum alignments of scalar fields can be given.

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arXiv2008

The economical SU(3)_C X SU(3)_L X U(1)_X model

In this report the SU(3)_C X SU(3)_L X U(1)_X gauge model with minimal scalar sector, two Higgs triplets, is presented in detail. One of the vacuum expectation values $u$ is a source of lepton-number violations and a reason for mixing among charged gauge bosons--the standard model W^\pm and the bilepton gauge bosons Y^\pm as well as among the neutral non-Hermitian bilepton X^0 and neutral gauge bosons--the Z and the new Z'. An exact diagonalization of the neutral gauge boson sector is derived and bilepton mass splitting is also given. Because of these mixings, the lepton-number violating interactions exist in both charged and neutral gauge boson sectors. Constraints on vacuum expectation values of the model are estimated and u \simeq O(1) GeV, v \simeq v_weak = 246 GeV, and ω\simeq O(1) TeV. In this model there are three physical scalars, two neutral and one charged, and eight Goldstone bosons--the needed number for massive gauge bosons. The minimal scalar sector can provide all fermions including quarks and neutrinos consistent masses in which some of them require one-loop radiative corrections.

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arXiv2008

Neutrino masses and lepton flavor violation in the 3-3-1 model with right-handed neutrinos

We show that in the framework of the 3-3-1 model with right-handed neutrinos, small neutrino masses and large lepton flavor violating processes such as μ\to 3e and μ\to eγcan be obtained by just introducing an additional Higgs sextet. In the limit of vanishing of the Yukawa interaction among Higgs and lepton triplets (h^ν= 0), the decay μ\to 3e strongly depends on the neutrino mass patterns, but the μ\to eγalmost does not. The neutrino masses are not constrained by such processes in the cases of h^ν\neq 0.

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arXiv2007

Sfermion masses in the supersymmetric economical 3-3-1 model

Sfermion masses and eigenstates in the supersymmetric economical 3-3-1 model are studied. By lepton number conservation, the exotic squarks and superpartners of ordinary quarks are decoupled. Due to the fact that in the 3-3-1 models, one generation of quarks behaves differently from other two, by R-parity conservation, the mass mixing matrix of the squarks in this model are smaller than that in the Minimal Supersymmetric Standard Model (MSSM). Assuming substantial mixing in pairs of highest flavours, we are able to get mass spectrum and eigenstates of all the sfermions. In the effective approximation, the slepton mass splittings in the first two generations, are consistent with those in the MSSM, namely: $ m^2_{\tilde{l}_L} - m^2_{\tildeν_{l L}} = m_W^2 \cos 2\ga$ $(l=e, μ)$. In addition, within the above effective limit, there exists degeneracy among sneutrinos in each multiplet: $m^2_{\tildeν_{l L}} = m^2_{\tildeν_{l R}}$. In contradiction to the MSSM, the squark mass splittings are different for each generation and not to be $ m_W^2 \cos 2\ga$.

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arXiv2007

Higgs phenomenology of supersymmetric economical 3-3-1 model

We explore the Higgs sector in the supersymmetric economical 3-3-1 model and find new features in this sector. The charged Higgs sector is revised i.e., in difference of the previous work, the exact eigenvalues and states are obtained without any approximation. In this model, there are three Higgs bosons having masses equal to that of the gauge bosons--the W and extra X and Y. There is one scalar boson with mass of 91.4 GeV, which is closed to the $Z$ boson mass and in good agreement with present limit: 89.8 GeV at 95% CL. The condition of eliminating for charged scalar tachyon leads to splitting of VEV at the first symmetry breaking, namely, $w \simeq w^\prime$. The interactions among the standard model gauge bosons and scalar fields in the framework of the supersymmetric economical 3-3-1 model are presented. From these couplings, at some limit, almost scalar Higgs fields can be recognized in accordance with the standard model. The hadronic cross section for production of the bilepton charged Higgs boson at the CERN LHC in the effective vector boson approximation is calculated. Numerical evaluation shows that the cross section can exceed 35.8 fb.

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arXiv2007

Supersymmetric economical 3-3-1 model

The supersymmetric extension of the economical 3-3-1 model is presented. The constraint equations and the gauge boson identification establish a relation between the vacuum expectation values (VEVs) at the top and bottom elements of the Higgs triplet $χ$ and its supersymmetric counterpart $χ^\prime$. Because of this relation, the exact diagonalization of neutral gauge boson sector has been performed. The gauge bosons and their associated Goldstone ones mix in the same way as in non-supersymmetric version. This is also correct in the case of gauginos. The eigenvalues and eigenstates in the Higgs sector are derived. The model contains a heavy neutral Higgs boson with mass equal to those of the neutral non-Hermitian gauge boson $X^0$ and a charged scalar with mass equal to those of the $W$ boson in the standard model, i. e. $ m_{\varrho_1} = m_W$. This result is in good agreement with the present estimation: $m_{H^\pm} > 79.3$ GeV, CL= 95 %. We also show that the boson sector and the fermion sector gain masses in the same way as in the non-supersymmetric case.

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arXiv2006

Neutrino masses in the economical 3-3-1 model

We show that, in frameworks of the economical 3-3-1 model, the suitable pattern of neutrino masses arises from the three quite different sources - the lepton-number conserving, the spontaneous lepton-number breaking and the explicit lepton-number violating, widely ranging over the mass scales including the GUT one: $u\sim O(1) \mathrm{GeV}$, $v\approx 246 \mathrm{GeV}$, $\om\sim O(1) \mathrm{TeV}$ and $\mathcal{M}\sim \mathcal{O}(10^{16}) \mathrm{GeV}$. At the tree-level, the model contains three Dirac neutrinos: one massless, two large with degenerate masses in the order of the electron mass. At the one-loop level, the left-handed and right-handed neutrinos obtain Majorana masses $M_{L,R}$ in orders of $10^{-2}-10^{-3} \mathrm{eV}$ and degenerate in $M_R=-M_L$, while the Dirac masses get a large reduction down to $\mathrm{eV}$ scale through a finite mass renormalization. In this model, the contributions of new physics are strongly signified, the degenerations in the masses and the last hierarchy between the Majorana and Dirac masses can be completely removed by heavy particles. All the neutrinos get mass and can fit the data.

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arXiv2006

Fermion masses in the economical 3-3-1 model

We show that, in frameworks of the economical 3-3-1 model, all fermions get masses. At the tree level, one up-quark and two down-quarks are massless, but the one-loop corrections give all quarks the consistent masses. This conclusion is in contradiction to the previous analysis in which, the third scalar triplet has been introduced. This result is based on the key properties of the model: First, there are three quite different scales of vacuum expectation values: $\om \sim {\cal O}(1) \mathrm{TeV}, v \approx 246 \mathrm{GeV}$ and $ u \sim {\cal O}(1) \mathrm{GeV}$. Second, there exist two types of Yukawa couplings with different strengths: the lepton-number conserving couplings $h$'s and the lepton-number violating ones $s$'s satisfying the condition in which the second are much smaller than the first ones: $ s \ll h$. With the acceptable set of parameters, numerical evaluation shows that in this model, masses of the exotic quarks also have different scales, namely, the $U$ exotic quark ($q_U = 2/3$) gains mass $m_U \approx 700 $ GeV, while the $D_\al$ exotic quarks ($q_{D_\al} = -1/3$) have masses in the TeV scale: $m_{D_\al} \in 10 ÷80$ TeV.

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arXiv2006

Atomic parity violation in the economical 3-3-1 model

The deviation $\de Q_{\mathrm{W}}$ of the weak charge from its standard model prediction due to the mixing of the $W$ boson with the charged bilepton $Y$ as well as of the $Z$ boson with the neutral $Z'$ and the real part of the non-Hermitian neutral bilepton $X$ in the economical 3-3-1 model is established. Additional contributions to the usual $\de Q_\mathrm{W}$ expression in the extra $\mathrm{U}(1)$ models and the left-right models are obtained. Our calculations are quite different from previous analyzes in this kind of the 3-3-1 models and give the limit on mass of the $Z'$ boson, the $Z-Z'$ and $W-Y$ mixing angles with the more appropriate values: $M_{Z'} > 564\ \mathrm{GeV}, -0.018<\sin \va < 0$ and $|\sin θ| < 0.043$.

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arXiv2006

Neutrino Masses in the Supersymmetric SU(3)_C X SU(3)_L X U(1)_X Model with right-handed neutrinos

The R-symmetry formalism is applied for the supersymmetric SU(3)_C X SU(3)_L X U(1)_X (3-3-1) model with right-handed neutrinos. For this kind of models, we study generalization of the MSSM relation among R-parity, spin and matter-parity. Discrete symmetries for the proton stable in this model are imposed, and we show that in such a case it is able to give leptons masses at only the tree level contributions required. A simple mechanism for the mass generation of the neutrinos is explored. We show that at the low-energy effective theory, neutrino spectrum contains three Dirac fermions, one massless and two degenerate in mass. At the energy-level where the mixing among them with neutralinos turned on, neutrinos obtain Majorana masses and correct the low-energy effective result which naturally gives rise to an inverted hierarchy mass pattern. This mass spectrum can fit the current data with minor fine-tuning. Consistent values for masses of the charged leptons are also given. In this model, the MSSM neutralinos and charginos can be explicitly identified in terms of the new constraints on masses which is not as in a supersymmetric version of the minimal 3-3-1 model.

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