Search

General expressions for one-loop contributions associated with the lepton-flavor violating decays of the standard model-like Higgs boson $h\to e_b^\pm e_a^\mp$ and gauge boson $Z\to e^\pm_b e_a^\mp$ are introduced in the unitary gauge. The results are used to discuss these decays as new physics signals in a minimal left-right symmetric model containing only one bidoublet Higgs and a $SU(2)_R$ Higgs doublet accommodating data of neutrino oscillations and $(g-2)_{\mu}$. The numerical investigation indicates that some of these decay rates can reach the near future experimental sensitivities., Comment: 39 pages, 4 figures

We investigate the 3-3-1 model with neutral leptons (called the 331$NL$ for short) and by that, we will point out that this model can simultaneously explain the lepton flavor violating (LFV) decays of the $Z$ boson $Z \to e_a e_b$, Standard model-like Higgs boson decay $h\to e_be_a$, and the charged leptons $e_b\to e_a \gamma$ consistent with the recent experimental data. In addition, the numerical results show strict relations among these decay rates of $Z$ and $h$ which are predicted by this model. As a result, the decay channels can be determined theoretically if one of them is detected by experiments., Comment: 24 pages, 5 figures

The lepton flavor violating (LFV) decays $h, Z\to e_b e_a $, and $e_b\to e_a \gamma$ are discussed in a class of general 3-3-1 models adding heavy neutral leptons and singly charged Higgs bosons to accommodate experimental data of neutrino oscillation and $(g-2)_{e_a}$ anomalies of charged leptons through the inverse seesaw mechanism. We show that the models with the minimal number of inverse seesaw neutrinos cannot reach the $1\sigma$ range of $(g-2)_{\mu}$ data due to the experimental upper bounds on decay rates of $(\tau \to \mu \gamma)$ and $(\mu \to e \gamma)$. Features of LFV decays are presented in detail, focusing on the regions of parameter space satisfying the $1\sigma$ ranges of $(g-2)_{e,\mu}$ data., Comment: 49 pages,9 figures. Accepted for publication in PRD

The lepton flavor violating decays $h\to e_b^\pm e_a^\mp $, $Z\to e_b^\pm e_a^\mp$, and $e_b\to e_a \gamma$ will be discussed in the framework of the Two Higgs doublet model with presence of new inverse seesaw neutrinos and a singly charged Higgs boson that accommodate both $1\sigma$ experimental data of $(g-2)$ anomalies of the muon and electron. Numerical results indicate that there exist regions of the parameter space supporting all experimental data of $(g-2)_{e,\mu}$ as well as the promising LFV signals corresponding to the future experimental sensitivities., Comment: Version accepted for publication in EPJC

Based on the Peccei-Quinn (PQ) assignment, the PQ charge operator in the 3-3-1 model with Cosmological Inflation is constructed in terms of diagonal generators $T_3$ and $T_8$ of the $SU(3)_L$ subgroup. The formula shows that difference of PQ charges of up and down quarks is 2, i.e., $\De Q_A =2$, while for electric charge, are assumed to be equal, while the ($Q_A$) are opposite. PQ charge of neutral scalars equal $\pm 2$, while for charged scalars, it vanishes. The couplings of axion with fermions are presented. To have correct kinetic term for the axion, the PQ scale $f_{a}$ is to be VEV of the singlet scalar boson, namely, $f_{a}= v_\phi$. The photon couples to charged particles only, while in this model, the axion does not couple to charged scalar/gauge bosons. The point is worth emphasizing that the axion has doubly derivative coupling with scalar playing the role of inflaton. The new effects mainly happen in the energy region from $10^7 \, \gev$ to $10^{11} \, GeV$. The chiral effective Lagrangian as usually provides axion mass consistent with model-independent prediction., Comment: 16 pages. Typos in Eqs. (14, 18, 69 , 72) and in Table III were corrected. Eq. (78) was added

A systematic study of one-loop contributions to the decay channels $h\rightarrow l\bar{l}\gamma$ with $l=\nu_{e,\mu, \tau}, e, \mu$, performed in Higgs extended versions of the Standard Model, is presented in the 't Hooft-Veltman gauge. Analytic formulas for one-loop form factors are expressed in terms of the logarithm and di-logarithmic functions. As a result, these form factors can be reduced to those relating to the loop-induced decay processes $h\rightarrow \gamma\gamma, Z\gamma$, confirming not only previous results using different approaches but also close relations between the three kinds of the loop-induced Higgs decay rates. For phenomenological study, we focus on the two observables, namely the enhancement factors defined as ratios of the decay rates calculated between the Higgs extended versions and the standard model, and the forward-backward asymmetries of fermions, which can be used to search for Higgs extensions of the SM. We show that direct effects of mixing between neutral Higgs bosons and indirect contributions of charged Higg boson exchanges can be probed at future colliders., Comment: 39 pages, 9 Figures, 11 Tables of data

We will show that the 3-4-1 model with heavy right-handed neutrinos can explain the recent experimental data of $(g-2)_{e, \mu}$ anomalies of charged leptons and neutrino oscillations through the inverse seesaw mechanism. In addition, the model can predict large lepton flavor violating decay rates $\mu \to e\gamma$ and $\tau \to \mu\gamma, e\gamma$ up to the recent experimental sensitivities., Comment: Version accepted for publication by PTEP, 31 pages, 8 figures

In this paper, we will present analytic formulas to express one-loop contributions to lepton flavor violating decays $e_b\to e_a \gamma$, which are also relevant to the anomalous dipole magnetic moments of charged leptons $e_a$. These formulas were computed in the unitary gauge, using the well-known Passarino-Veltman notations. We also show that our results are consistent with those calculated previously in the 't Hooft-Veltman gauge, or in the limit of zero lepton masses. At the one-loop level, we show that the appearance of fermion-scalar-vector type diagrams in the unitary gauge will violate the Ward Identity relating to an external photon. As a result, the validation of the Ward Identity guarantees that the photon always couples with two identical particles in an arbitrary triple coupling vertex containing a photon., Comment: The version accepted to Nuclear Physics B

We will show that the 3-3-1 model with new heavy right handed neutrinos as $SU(3)_L$ singlets can explain simultaneously the lepton flavor violating decays of the SM-like Higgs boson, charged lepton flavor violating decays $e_b\rightarrow e_a\gamma$, and the electron $(g-2)_e$ anomalies under recent experimental data. The discrepancy of $(g-2)_{\mu}$ predicted by the model under consideration and that of the standard model can reach $10^{-9}$. The decay rates of the standard model-like Higgs boson $h\to \tau e, \tau\mu$ can reach the values of $\mathcal{O}(10^{-4})$., Comment: 35 pages, new references were added, numerical investigations were changed, version accepted for publication in PTEP

We show that simple extensions of two Higgs doublet models consisting of new heavy neutrinos and a singly charged Higgs boson singlet can successfully explain the experimental data on muon and electron anomalous magnetic moments thanks to large chirally-enhanced one-loop level contributions. These contributions arise from the large couplings of inverse seesaw neutrinos with singly charged Higgs bosons and right-handed charged leptons. The regions of parameter space satisfying the experimental data on $(g-2)_{e,\mu}$ anomalies allow heavy singly charged Higgs boson masses above the TeV scale, provided that heavy neutrino masses are above few hundred GeV, the non-unitary part of the active neutrino mixing matrix must be large enough, two singly charged Higgs bosons are non degenerate, and the mixing between singly charged Higgs bosons must be non-zero., Comment: 30 pages, 9 figures. Numerical results were corrected. New references were added. Version accepted for publication in NPB

We investigate coherent-elastic neutrino-nucleus scattering ($CE\nu NS$) in 3-3-1 models for different values of $\beta$ in which $\beta$ is a parameter used to define the charge operator of the 331 models. We show that the number of events predicted by 331$\beta$ model is in agreement with the data given by COHERENT experiment. We evaluate the sensitivity of the mass of Z' boson with 90% confidence level (CL) and find that $m_{Z'}\geq 1.4 $TeV for $\beta=-\sqrt{3}$ with 90% CL. We perform $\chi^2$ fit for liquid Argon, Germanium and NaI detector subsystems, we obtain $m_{Z'} \geq [2,3.1 ]$ TeV with 90\% CL. Our results indicate low-energy high-intensity measurements can provide a valuable probe, complementary to high energy collider searches at LHC and electroweak precision measurements.

We show that the anomalous magnetic moment experimental data of muon and electron $(g-2)_{\mu,e}$ can be explained simultaneously in simple extensions of the 3-3-1 models consisting of new heavy neutrinos and a singly charged Higgs boson. The heavy neutrinos generate active neutrino masses and mixing through the general seesaw mechanism. They also have non-zero Yukawa couplings with singly charged Higgs bosons and right-handed charged leptons, which result in large one-loop contributions known as \emph{chirally-enhanced} ones. Numerical investigation confirms a conclusion indicated previously that these contributions are the key point to explain the large $(g-2)_{\mu,e}$ data, provided that the inverse seesaw mechanism is necessary to allow both conditions that heavy neutrino masses are above few hundred GeV and non-unitary part of the active neutrino mixing matrix must be large enough., Comment: 43 pages,6 Figures. Numerical results and typos are corrected. New references are added

We show that under current experimental bound of the decays $e_a\rightarrow e_b\gamma$, the recent experimental data of the muon anomalous magnetic dipole moment $(g-2)_{\mu}$ can be explained in the framework of the 3-3-1 model with right handed neutrinos. In addition, all of these branching ratios can reach closely the recent experimental upper bounds., Comment: The version accepted to PRD

The stellar energy-loss rates $\mathcal{Q}$ due to the production of neutrino pair in the framework of 3-3-1 models are presented. The energy loss rate $\mathcal{Q}$ is evaluated for different values of $\beta=\pm\fr{1}{\sqrt{3}},\pm\fr{2}{\sqrt{3}},\pm\sqrt{3}$ in which $\beta$ is a parameter used to define the charge operator in the 3-3-1 models. The correction to the rate which is compared with that of the Standard Model ($\de \mathcal{Q}$) is also evaluated. We show that the correction does not exceed 14\% and %is gets the highest with $\beta=-\sqrt{3}$. The contribution of dipole moment to the energy loss rate is small compared to the contribution of new natural gauge boson $Z'$ and this sets constraints for the mass of Z' $m_{Z'} \leq 4000$ GeV. This mass range is within the searching range for $Z'$ boson at LHC., Comment: Revised version, new references added. arXiv admin note: text overlap with arXiv:2005.03808 by other authors

An extension of the two Higgs doublet model including inverse seesaw neutrinos and neutral Higgs bosons was constructed based on the $A_4$ symmetry in order to explain the recent neutrino oscillation data. This model can distinguish two well-known normal and inverted order schemes of neutrino data once both the effective masses $m_{\beta}$ in tritium beta decays and $\langle m\rangle$ in the neutrinoless double beta decay are observed. The lepton flavor violating decays of the charged leptons $e_b\rightarrow e_a\gamma$, $\mu\rightarrow3e$, the Standard model-like Higgs boson decays $h\rightarrow e_be_a$, and the $\mu$-e conversions in some nuclei are generated from loop corrections. The experimental data of the branching ratio Br$(\mu\rightarrow e\gamma, 3e)$ predict that the upper bounds of Br$(\tau \rightarrow \mu\gamma,e\gamma)$ and Br$(h\rightarrow e_{a}e_b)$ are much smaller than the planned experimental sensitivities. In contrast, the $\mu$-e conversions are the promising signals for experiments., Comment: Matching the published version in PTEP

In the framework of the flipped 3-3-1 model introduced recently [1], the lepton-flavor-violating (LFV) decay $\mu \rightarrow 3e$ was predicted to have a large branching ratio (Br) close to the recent experimental limit. We will show that the Br of LFV decays of the standard-model-like (SM-like) Higgs boson decays (LFVHD) Br$(h\rightarrow e_ae_b)$ may also be large. Namely, the Br$(h\rightarrow \mu\tau,e\tau)$ can reach values of $\mathcal{O}(10^{-4})-\mathcal{O}(10^{-5})$, which will reach the upcoming experimental sensitivities. On the other hand, for LFV decays of charged leptons (cLFV) $(e_b\rightarrow e_a\gamma)$, the branching ratios are well below experimental bounds., Comment: Typos corrected based on the version published in PTEP. References added

Low energy linear seesaw mechanism responsible for the generation of the tiny active neutrino masses, is implemented in the extended 3-3-1 model with two scalar triplets and right handed Majorana neutrinos where the gauge symmetry is supplemented by the $A_4$ flavor discrete group and other auxiliary cyclic symmetries, whose spontaneous breaking produces the observed pattern of SM charged fermion masses and fermionic mixing parameters. Our model is consistent with the low energy SM fermion flavor data as well as with the constraints arising from meson oscillations. Some phenomenological aspects such as the $Z^\prime$ production at proton proton collider and the lepton flavor violating decay of the SM-like Higgs boson are discussed. The scalar potential of the model is analyzed in detail and the SM-like Higgs boson is identified., Comment: Version accepted for publication in European Physical Journal Plus

The significance of new physics appearing in the loop-induced decays of neutral Higgs bosons into pairs of dibosons $\gamma\gamma$ and $Z\gamma$ will be discussed in the framework of the 3-3-1 models based on a recent work~\cite{Okada:2016whh}, where the Higgs sector becomes effectively the same as that in the two Higgs doublet models (2HDM) after the first symmetry breaking from $SU(3)_L$ scale into the electroweak scale. For large $SU(3)_L$ scale $v_3\simeq10$ TeV, dominant one-loop contributions to the two decay amplitudes arise from only the single charged Higgs boson predicted by the 2HDM, leading to that experimental constraint on the signal strength $\mu^{331}_{\gamma\gamma}$ of the Standard Model-like Higgs boson decay $h\rightarrow \gamma\gamma$ will result in a strict upper bound on the signal strength $\mu^{331}_{Z\gamma}$ of the decay $h\rightarrow\, Z\gamma$. For a particular model with lower $v_3$ around 3 TeV, contributions from heavy charged gauge and Higgs bosons may have the same order, therefore may give strong destructive or constructive correlations. As a by-product, a deviation from the SM prediction $|\mu^{331}_{\gamma\gamma}-1| \le 0.04$ still allows $|\mu^{331}_{Z\gamma}-1|$ to reach values near 0.1. We also show that there exists an $CP$-even neutral Higgs boson $h^0_3$ predicted by the 3-3-1 models, but beyond the 2HDM, has an interesting property that the branching ratio Br$(h^0_3\rightarrow \gamma\gamma)$ is very sensitive to the parameter $\beta$ used to distinguish different 3-3-1 models., Comment: Version accepted for publication in PRD

The recent experimental data of the weak charges of Cesium and proton is analyzed in the framework of the models based on the $\mbox{SU}(3)_C\times \mbox{SU}(3)_L \times \mbox{U}(1)_X$ (3-3-1) gauge group, including the 3-3-1 model with CKS mechanism (3-3-1CKS) and the general 3-3-1 models with arbitrary $\beta$ (3-3-1$\beta$) with three Higgs triplets. We will show that at the TeV scale, the mixing among neutral gauge bosons plays significant effect. Within the present values of the weak charges of Cesium and proton we get the lowest mass bound of the extra heavy neutral gauge boson to be 1.27 TeV. The results derived from the weak charge data, perturbative limit of Yukawa coupling of the top quark, and the relevant Landau poles favor the models with $\beta =\pm 1/\sqrt{3}$ and $\beta = 0$ while ruling out the ones with $\beta= \pm \sqrt{3}$. In addition, there are some hints showing that in the 3-3-1 models, the third quark family should be treated differently from the first twos., Comment: 33 pages, 9 figures, title changed, improved version accepted for publication in NPB

We perform a comprehensive analysis of several phenomenological aspects of the renormalizable extension of the inert 3-3-1 model with sequentially loop-generated SM fermion mass hierarchy. Special attention is paid to the study of the constraints arising from the experimental data on the $\rho$ parameter, as well as those ones resulting from the charged lepton flavor violating process $\mu\to e\gamma$ and dark matter. We also study the single $Z'$ production via Drell-Yan mechanism at the LHC. We have found that $Z'$ gauge bosons heavier than about $4$ TeV comply with the experimental constraints on the oblique $\rho$ parameter as well as with the collider constraints. In addition, we have found that the constraint on the charged lepton flavor violating decay $\mu\rightarrow e\gamma$ sets the sterile neutrino masses to be lighter than about $1.12$ TeV. In addition the model allows charged lepton flavor violating processes within reach of the forthcoming experiments. The scalar potential and the gauge sector of the model are analyzed and discussed in detail. Our model successfully accommodates the observed Dark matter relic density., Comment: Version accepted for publication in PRD

By adding new gauge singlets of neutral leptons, the improved versions of the 3-3-1 models with right-handed neutrinos have been recently introduced in order to explain recent experimental neutrino oscillation data through the inverse seesaw mechanism. We prove that these models predict promising signals of lepton-flavor-violating decays of the standard-model-like Higgs boson $h^0_1\rightarrow \mu\tau,e\tau$, which are suppressed in the original versions. One-loop contributions to these decay amplitudes are introduced in the unitary gauge. Based on a numerical investigation, we find that the branching ratios of the decays $h^0_1\rightarrow\mu\tau,e\tau$ can reach values of $10^{-5}$ in the regions of parameter space satisfying the current experimental data of the decay $\mu\rightarrow e\gamma$. The value of $10^{-4}$ appears when the Yukawa couplings of leptons are close to the perturbative limit. Some interesting properties of these regions of parameter space are also discussed., Comment: 31 pages, 5 figures. Version accepted for publication in PRD

Radiative corrections to the $h\rightarrow Z\gamma$ are evaluated in the one-loop approximation. The unitary gauge gauge is used. The analytic result is expressed in terms of the Passarino-Veltman functions. The calculations are applicable for the Standard Model as well for a wide class of its gauge extensions. In particular, the decay width of a charged Higgs boson $H^\pm \rightarrow W^\pm\gamma$ can be derived. The consistence of our formulas and several specific earlier results is shown., Comment: 33 pages, 3 figures, a new section (V) and references were improved in the published version

We will investigate numerically a seesaw model with $A_4$ flavor symmetry to find allowed regions satisfying the current experimental neutrino oscillation data, then use them to predict physical consequences. Namely, the lightest active neutrino mass has order of $\mathcal{O}(10^{-2})$ eV. The effective neutrino mass $|\langle m\rangle|$ associated with neutrinoless double beta decay is in the range of $[0.002 \;\mathrm{eV},0.038\;\mathrm{eV}]$ and $[0.048\;\mathrm{eV},0.058\;\mathrm{eV}]$ corresponding to the normal and the inverted hierarchy schemes. Other relations among relevant physical quantities are shown, so that they can be determined if some of them are confirmed experimentally. The recent data of the baryon asymmetry of the Universe ($\eta_B$) can be explained via leptogenesis caused by the effect of the renormalization group evolution on the Dirac Yukawa couplings, provided the right handed neutrino mass scale $M_0$ is ranging from $\mathcal{O}(10^8)$ GeV to $\mathcal{O}(10^{12})$ GeV for $\tan\beta =3$. This allowed $M_0$ range distinguishes with the scale of $\mathcal{O}(10^{13})$ GeV concerned by other effects that also generate the consistent $\eta_B$ from leptogenesis. The branching ratio of the decay $ \mu \rightarrow\,e\gamma$ may reach the future experimental sensitivity in the very light values of $M_0$. Hence, it will be inconsistent with the $M_0$ range predicted from the $\eta_B$ data whenever this decay is detected experimentally., Comment: The accepted version to PTEP

We investigate the decays $l_i\rightarrow l_j \gamma$, with $l_i=e,\mu,\tau$ in a general class of 3-3-1 models with heavy exotic leptons with arbitrary electric charges. We present full and exact analytical results keeping external lepton masses. As a by product, we perform numerical comparisons between exact results and approximate ones where the external lepton masses are neglected. As expected, we found that branching fractions can reach the current experimental limits if mixings and mass differences of the exotic leptons are large enough. We also found unexpectedly that, depending on the parameter values, there can be huge destructive interference between the gauge and Higgs contributions when the gauge bosons connecting the Standard Model leptons to the exotic leptons are light enough. This mechanism should be taken into account when using experimental constraints on the branching fractions to exclude the parameter space of the model., Comment: 27 pages, 5 figures, 4 tables; additional explanation on input parameters; matches journal version

The lepton flavor violating decay of the Standard Model-like Higgs boson (LFVHD), h->\mu\tau, is discussed in seesaw models at the one-loop level. Based on particular analytic expressions of Passarino-Veltman functions, the two unitary and 't Hooft Feynman gauges are used to compute the branching ratio of LFVHD and compare with results reported recently. In the minimal seesaw (MSS) model, the branching ratio was investigated in the whole valid range 10^{-9}-10^{15} GeV of new neutrino mass scale m_{n_6}. Using the Casas-Ibarra parameterization, this branching ratio enhances with large and increasing m_{n_6}. But the maximal value can reach only order of 10^{-11}. Interesting relations of LFVHD predicted by the MSS and inverse seesaw (ISS) model are discussed. The ratio between two LFVHD branching ratios predicted by the ISS and MSS is simply m^2_{n_6}\mu^{-2}_X, where \mu_X is the small neutrino mass scale in the ISS. The consistence between different calculations is shown precisely from analytical approach., Comment: 4 figures, 26 pages, some analytic formulas and statements are corrected. Main results are unchanged. New references added. Version published in NPB

The neutrino and Higgs sectors in the $\mbox{SU(2)}_1 \times \mbox{SU(2)}_2 \times \mbox{U(1)}_Y $ model with lepton-flavor non-universality are discussed. We show that active neutrinos can get Majorana masses from radiative corrections, after adding only new singly charged Higgs bosons. The mechanism for generation of neutrino masses is the same as in the Zee models. This also gives a hint to solving the dark matter problem based on similar ways discussed recently in many radiative neutrino mass models with dark matter. Except the active neutrinos, the appearance of singly charged Higgs bosons and dark matter does not affect significantly the physical spectrum of all particles in the original model. We indicate this point by investigating the Higgs sector in both cases before and after singly charged scalars are added into it. Many interesting properties of physical Higgs bosons, which were not shown previously, are explored. In particular, the mass matrices of charged and CP-odd Higgs fields are proportional to the coefficient of triple Higgs coupling $\mu$. The mass eigenstates and eigenvalues in the CP-even Higgs sector are also presented. All couplings of the SM-like Higgs boson to normal fermions and gauge bosons are different from the SM predictions by a factor $c_h$, which must satisfy the recent global fit of experimental data, namely $0.995<|c_h|<1$. We have analyzed a more general diagonalization of gauge boson mass matrices, then we show that the ratio of the tangents of the $W-W'$ and $Z-Z'$ mixing angles is exactly the cosine of the Weinberg angle, implying that number of parameters is reduced by 1. Signals of new physics from decays of new heavy fermions and Higgs bosons at LHC and constraints of their masses are also discussed., Comment: 40 pages, 1 figure; Journal vesion

This paper includes two main parts. In the first part, we present generalized gauge models based on SU(3)_C x SU(4)_L x U(1)_X (3-4-1) gauge group with arbitrary electric charge of leptons. The mixing matrix of neutral gauge bosons is analysed, the eigenmasses and eigenstates are obtained. The anomaly free as well as matching conditions are discussed precisely. In the second part, we present new development of the original 3-4-1 model [1,2]. In difference from previous works, in this paper the neutrinos, with the help of the decuplet H, get the Dirac masses at the tree level. The VEV of the Higgs field in the decuplet H acquiring VEV responsible for neutrino Dirac mass leads to mixing in separated pairs of singly charged gauge bosons, namely the SM W boson and K - new gauge boson acting in right-handed lepton sector, and the singly charged bileptons X and Y. Due to the mixing, there occurs a right-handed current carried by the SM W bosons. From the expression of the electromagnetic coupling constant, ones get the limit of square sinus of the Weinberg angle: sin^2 \theta_W < 0.25 and a constraint on electric charges of extra leptons. In the limit of lepton number conservation, the Higgs sector contains all massless Goldstone bosons for massive gauge bosons and the SM-like Higgs. Some phenomenology are pointed out., Comment: 41 pages, the published version

In calculating one-loop contributions to amplitudes of the lepton-flavor violating decays of the neutral Higgses (LFVHD) to different flavor charged leptons, the analytic expressions can be written in term of Passarino-Veltman functions. Then, they can be computed numerically by Looptools [1]. Another approach is using suitable analytic expressions established for just this particular case. We compare numerical results obtained from Looptools and those computed by different expressions that have been applied recently. Then we derive the preferable ones that are applicable for the large ranges of free parameters introduced in the models beyond the Standard Model (SM). For illustration, the LFVHD in a simple model, which has been discussed recently, will be investigated more precisely., Comment: Improved version accepted by PTEP. New discussions and references are added

The lepton flavor violating decay of the Standard Model-like Higgs (LFVHD) is discussed in the framework of the radiative neutrino mass model built in \cite{Kenji}. The branching ratio (BR) of the LFVHD are shown to reach $10^{-5}$ in the most interesting region of the parameter space shown in \cite{Kenji}. The dominant contributions come from the singly charged Higgs mediations, namely the coupling of $h^\pm_2$ with exotic neutrinos. Furthermore, if doubly charged Higgs is heavy enough to allow the mass of $h^\pm_2$ around 1 TeV, the mentioned BR can reach $10^{-4}$. Besides, we have obtained that the large values of the Br$(h\rightarrow\mu\tau)$ leads to very small ones of the Br$(h\rightarrow e\tau)$, much smaller than various sensitivity of current experiments., Comment: 25 pages, 7 figures, matches published version in PRD

The one loop contribution to the lepton flavor violating decay $h^0\rightarrow \mu\tau$ of the SM-like neutral Higgs (LFVHD) in the 3-3-1 model with neutral lepton is calculated using the unitary gauge. We have checked in detail that the total contribution is exactly finite, and the divergent cancellations happen separately in two parts of active neutrinos and exotic heavy leptons. By numerical investigation, we have indicated that the one-loop contribution of the active neutrinos is very suppressed while that of exotic leptons is rather large. The branching ratio of the LFVHD strongly depends on the Yukawa couplings between exotic leptons and $SU(3)_L$ Higgs triplets. This ratio can reach $10^{-5}$ providing large Yukawa couplings and constructive correlations of the $SU(3)_L$ scale ($v_3$) and the charged Higgs masses. The branching ratio decreases rapidly with the small Yukawa couplings and large $v_3$., Comment: 47 pages, 7 figures, references added, Journal version to appear in Nucl. Phys. B

Masses and signals of the production of Doubly charged Higgses(DCH) in the framework of the supersymmetric reduced minimal 3-3-1 model(SUSYRM331) are investigated. In the DCH sector, weprove that there always exists a region of the parameter space where the mass of the lightest DCH is in order of $\mathcal{O}(100)$ GeV even when all other new particles are very heavy.The lightest DCH mainly decays to two same-sign leptons while the dominated decay channels of the heavy DCHs are those decay to heavy particles. We analyze each production cross section for $e^+e^- \rightarrow H^{++} H^{--}$ as a function of a few kinematic variables, which are useful to discuss the creation of the DCHs in the $e^+e^-$ colliders as a signal of new physics beyond the Standard Model. The numerical study shows that the cross sections for creating the lightest DCH can reach values of few pbs. The two other DCHs are too heavy, beyond the observable range of experiments. The lightest DCH may be detected by the International Linear Collider (ILC) or the Compact LInear Collider (CLIC) by searching its decay to a same-sign charged lepton pair., Comment: 48 pages, 22 figures, more considerations included, accepted for publication in PTEP

We re-investigate the scalar potential and the Higgs sector of the supersymmetric economical 3-3-1 model (SUSYE331) in the presence of the B/\mu type terms which has many important consequences. First, the model contains no massless Higgs fields. Second, we prove that the soft mass parameters of Higgses must be at the SU(3)_L scale. As a result, the masses of the Higgses drift toward this scale except one light real neutral Higgs with the mass of m_Z|cos(2\gamma)| at the tree level. We also show that there are some Higgses containing many properties of the Higgses in the minimal supersymmetric standard model (MSSM), especially in the neutral Higgs sector. One exact relation in the MSSM, m^2_H^{+/-}=m^2_A+m^2_W, is still true in the SUSYE331. Based on this result we make some comments on the lepton flavor violating decays of these Higgses as one of signatures of new physics in the SUSYE331 model which may be detected by present colliders., Comment: Matches version accepted for publication in EPJC. Typos are corrected. We add a new section, a new appendix, a new figure and new references to explain more clearly the properties of the lightest neutral Higgs. Results unchanged

In this work, we study the charged lepton flavor violating (cLFV) decays $\tau-> \mu\gamma$, $\tau-> 3\mu$ and $Z->\mu\tau$ in the framework of the Supersymmetric economical 3-3-1 model. Analytic formulas for branching ratios (BR) of these decays are presented. We assume that there exist lepton flavor violation (LFV) sources in both right- and left-handed slepton sectors. This leads to the strong enhancement of cLFV decay rates. We also show that the effects of the LFV source to the cLFV decay rates in the left-handed slepton sector are greater than those in the right- handed slepton sector. By numerical investigation, we show that the model under consideration contains the relative light mass spectrum of sleptons which satisfies the current experimental bounds on LFV processes in the limit of small $\tan \gamma$. The interplay between monopole and dipole operators also was studied., Comment: $B/\mu$-type parameters are included to guarantee the vacuum stability condition as well as satisfy current electroweak precision test. Mass parameter of gaugino in numerical investigation is shifted to be larger than 300 GeV. Few conclusions are changed. New references are added. This version was accepted by Nuclear Physics B

We build an supersymmetric version of the minimal 3-3-1 model with just two Higgs triplets using the superfield formalism. We study the mass spectrum of all particles in concordance with the experimental bounds. At the tree level, the masses of charged gauge bosons are the same as those of charged Higgs bosons. We also show that the electron, muon and their neutrinos as well as down and strange quarks gain mass through the loop correction. The narrow constraint on the ratio t_w = \frac{w}{w^\prime} is given by studying the new invisible decay mode of the Z boson., Comment: Journal version, 4 pictures are added for more details in explanation the generating masses of leptons

We investigate Lepton-Flavor Violating (LFV) decays of Higgs to muon-tau in the supersymmetric economical 3-3-1 (SUSYE331) model. In the presence of flavor mixing in sleptons {mu,tau} and large values of v/v', the ratio of Br(H -->tau^+mu^-)/Br(H -->tau^+tau^-) can reach to non-negligible values O(10^{-3}), as in many known SUSY models. We predict that for the Standard Model Higgs boson, the LHC may detect its decay to muon and tauon. We also investigate the asymmetry between left and right LFV values of corrections and prove that the LFV effects are dominated by the left FLV term, which is O(10^3) times larger than the right LFV term in the limit of small values of |\mu_\rho|/m_SUSY. The contributions of Higgs-mediated effects to the decay tau --> mu mu mu are also discussed., Comment: Journal version

General formula for symmetry factors (S-factor) of Feynman diagrams containing fields with high spins is derived. We prove that symmetry factors of Feynman diagrams of well-known theories do not depend on spins of fields. In contributions to S-factors, self-conjugate fields and non self-conjugate fields play the same roles as real scalar fields and complex scalar fields, respectively. Thus, the formula of S-factors for scalar theories --- theories include only real and complex scalar fields --- works on all well-known theories of fields with high spins.Two interesting consequences deduced from our result are : (i) S-factors of all external connected diagrams consisting of only vertices with three different fields, e.g., spinor QED, are equal to unity; (ii) some diagrams with different topologies can contribute the same factor, leading to the result that the inverse S-factor for the total contribution is the sum of inverse S-factors, i.e., 1/S = \sum_i (1/S_i)., Comment: 22 pages, wick.sty needed, revised version, reference added, accepted in Reports on Mathematical Physics

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., Comment: Version published by PRD

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)., Comment: Journal version, new references added