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L. T. Hue

Publications and source records attributed to L. T. Hue.

At least 37 records · Page 2Linked to original sources
arXiv2021

COHERENT constraints on $Z'$ in 331$β$ model

We investigate coherent-elastic neutrino-nucleus scattering ($CEνNS$) in 3-3-1 models for different values of $β$ in which $β$ is a parameter used to define the charge operator of the 331 models. We show that the number of events predicted by 331$β$ 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 $β=-\sqrt{3}$ with 90% CL. We perform $χ^2$ 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.

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arXiv2021

Neutrino Energy Loss Rates in 3-3-1 Models

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 $β=\pm\fr{1}{\sqrt{3}},\pm\fr{2}{\sqrt{3}},\pm\sqrt{3}$ in which $β$ 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 $β=-\sqrt{3}$. 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.

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arXiv2020

Lepton flavor violating decays of the SM-like Higgs boson $h\rightarrow e_ie_j$, and $e_i \rightarrow e_j\, γ$ in a flipped 3-3-1 model

In the framework of the flipped 3-3-1 model introduced recently [1], the lepton-flavor-violating (LFV) decay $μ\rightarrow 3e$ 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$(h\rightarrow μτ,eτ)$ 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) $(e_b\rightarrow e_aγ)$, the branching ratios are well below experimental bounds.

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arXiv2020

CP violations in a predictive $A_4$ symmetry model

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 ($η_B$) 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 $\tanβ=3$. This allowed $M_0$ range distinguishes with the scale of $\mathcal{O}(10^{13})$ GeV concerned by other effects that also generate the consistent $η_B$ from leptogenesis. The branching ratio of the decay $ μ\rightarrow\,eγ$ 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 $η_B$ data whenever this decay is detected experimentally.

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arXiv2019

Neutral Higgs decays $H \rightarrow Z γ,γγ$ in 3-3-1 models

The significance of new physics appearing in the loop-induced decays of neutral Higgs bosons into pairs of dibosons $γγ$ and $Zγ$ 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 $μ^{331}_{γγ}$ of the Standard Model-like Higgs boson decay $h\rightarrow γγ$ will result in a strict upper bound on the signal strength $μ^{331}_{Zγ}$ of the decay $h\rightarrow\, Zγ$. 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 $|μ^{331}_{γγ}-1| \le 0.04$ still allows $|μ^{331}_{Zγ}-1|$ 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$(h^0_3\rightarrow γγ)$ is very sensitive to the parameter $β$ used to distinguish different 3-3-1 models.

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arXiv2019

Higgs and gauge boson phenomenology of the 3-3-1 model with CKS mechanism

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 $ρ$ parameter, as well as those ones resulting from the charged lepton flavor violating process $μ\to eγ$ 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 $ρ$ parameter as well as with the collider constraints. In addition, we have found that the constraint on the charged lepton flavor violating decay $μ\rightarrow eγ$ 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.

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arXiv2019

Constraining heavy neutral gauge boson $Z'$ in the 3 - 3 - 1 models by weak charge data of Cesium and proton

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 $β$ (3-3-1$β$) 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 $β=\pm 1/\sqrt{3}$ and $β= 0$ while ruling out the ones with $β= \pm \sqrt{3}$. 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.

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arXiv2018

General one-loop formulas for decay $h\rightarrow Zγ$

Radiative corrections to the $h\rightarrow Zγ$ 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 $H^\pm \rightarrow W^\pmγ$ can be derived. The consistence of our formulas and several specific earlier results is shown.

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arXiv2018

Decay of standard model-like Higgs boson $h\rightarrow μτ$ in a 3-3-1 model with inverse seesaw neutrino masses

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 $h^0_1\rightarrow μτ,eτ$, 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 $h^0_1\rightarrowμτ,eτ$ can reach values of $10^{-5}$ in the regions of parameter space satisfying the current experimental data of the decay $μ\rightarrow eγ$. 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.

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arXiv2018

Exact one-loop results for $l_i \to l_jγ$ in 3-3-1 models

We investigate the decays $l_i\rightarrow l_j γ$, with $l_i=e,μ,τ$ 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.

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arXiv2017

Lepton flavor violating Higgs boson decays in seesaw models: new discussions

The lepton flavor violating decay of the Standard Model-like Higgs boson (LFVHD), h->μτ, 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}μ^{-2}_X, where μ_X is the small neutrino mass scale in the ISS. The consistence between different calculations is shown precisely from analytical approach.

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arXiv2017

Probing neutrino and Higgs sectors in $SU(2)_1 \times SU(2)_2 \times U(1)_Y$ model with lepton-flavor non-universality

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 $μ$. 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.

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arXiv2016

One loop contributions to neutral Higgs decay h-->mu tau

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.

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arXiv2016

The electroweak theory based on SU(4)_L X U(1)_X gauge group

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 θ_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.

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arXiv2016

Lepton flavor violating decay of SM-like Higgs in a radiative neutrino mass model

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$(h\rightarrowμτ)$ leads to very small ones of the Br$(h\rightarrow eτ)$, much smaller than various sensitivity of current experiments.

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arXiv2016

Lepton flavor violating decays of Standard-Model-like Higgs in 3-3-1 model with neutral lepton

The one loop contribution to the lepton flavor violating decay $h^0\rightarrow μτ$ 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 $v_3$.

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arXiv2015

Signal of doubly charged Higgs at $e^+e^-$ colliders

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.

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