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H. N. Long

Publications and source records attributed to H. N. Long.

88 records · Page 5Linked to original sources
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

Right-handed sneutrinos as self-interacting dark matter in supersymmetric economical 3-3-1 model

In this work we show that the supersymmetric economical SU(3)_C X SU(3)_L X U(1)_X (3-3-1) gauge model has a realistic candidate for self-interacting dark matter. In the model under consideration, the right-handed sneutrino is in bottom of the triplet, which is a singlet of the Standard Model SU(2)_L group. In addition, the right-handed sneutrino is the lightest slepton. By these properties, the right-handed sneutrino is weakly interacting with the Standard Model and stable without introduction of extra symmetry. From the Spergel-Steinhardt condition, the typical mass limit $\leq 10 $ MeV is derived. With self-interacting coupling constant fixed by supersymmetry, this limit is deduced without any approximation. The condition for thermal generated self-interacting dark matter in the Universe is also obtained.

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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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arXiv2006

SU(3)_C X SU(3)_L X U(1)_X model with two Higgs triplets

The $SU(3)_C X SU(3)_L X U(1)_X$ gauge model with the minimal scalar sector (two Higgs triplets) is studied in detail. One of the vacuum expectation values $u$ is a source of lepton-number violations and a reason for the mixing among the charged gauge bosons - the standard model $W$ and the bilepton (with L=2) gauge bosons as well as among neutral non-Hermitian $X^0$ and neutral gauge bosons: the photon, the $Z$ and the new $Z'$. Because of these mixings, the lepton-number violating interactions exist in both charged and neutral gauge boson sectors. An exact diagonalization of the neutral gauge boson sector is derived and bilepton mass splitting is also given. The lepton-number violation happens only in the neutrino but not in the charged lepton sector. In this model, lepton-number changing ($ΔL = \pm 2$) processes exist but "only" in the neutrino sector. Constraints on VEVs of the model are estimated and $u \simeq \emph{O}(1) \textrm{GeV}$, $v \simeq v_{weak} = 246 \textrm{GeV}$ and $\om \simeq \emph{O}(1) \textrm{TeV}$.

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arXiv2005

Scalar sector of Supersymmetric ${SU}(3)_C\otimes {SU}(3)_L \otimes {U}(1)_N$ Model with right-handed neutrinos

We investigate a scalar sector of the supersymmetric $ SU_C(3) \otimes SU_L(3)\otimes U_N(1)$ model with right-handed neutrinos. The mass spectra are derived. We show that only neutral Higgs sector with lepton number L=0 could have a VEV. There is no mixing between scalars having L=0 and bilepton scalars having L=2. There are six Goldstone bosons: two in neutral sector, three in pseudo-scalar sector and one in charged scalar sector. For a given set of input parameters (five from the $F$ terms and two from the soft term) all the scalar sectors in this model contain the upper limit of 230 GeV to the mass of the lightest scalar, which are in agreement with the lower limit of the SM Higgs boson obtained by LEP.

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arXiv2003

Single Z' production at CLIC based on e^- gamma collisions

We analyze the potential of CLIC based on e- gamma collisions to search for new $Z'$ gauge boson. Single Z' production at e-gamma colliders in two SU(3)_C X SU(3)_L X U(1)_N models: the minimal model and the model with right-handed (RH) neutrinos is studied in detail. Results show that new Z' gauge bosons can be observed at the CLIC, and the cross sections in the model with RH neutrinos are bigger than those in the minimal one.

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arXiv2003

Bilepton production in electron-gamma collisions

We study the production of bileptons, new gauge boson of lepton number two, in the minimal 3 - 3 - 1 model in high energy electron - photon collisions. If the bilepton masses are in the range of 300 GeV the reaction will give observable cross-sections in the future colliders.

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arXiv2000

On the Quark-Quark Superconducting Pairing Induced by Instantons in QCD

The superconducting pairing of quarks induced by instantons in QCD is studied by means of the functional integral method. The integral equation determining the critical temperature of the superconducting phase transition is established. It is shown that the Bose condensate of diquarks consists of color antitriplet $(\bar{3}) $ scalar diquarks

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