scholarly journals The EconomicalSU(3)C⊗SU(3)L⊗U(1)XModel

2008 ◽  
Vol 2008 ◽  
pp. 1-74 ◽  
Author(s):  
P. V. Dong ◽  
H. N. Long

TheSU(3)C⊗SU(3)L⊗U(1)Xgauge model with minimal scalar sector, two Higgs triplets, is presented in detail. One of the vacuum expectation valuesuis a source of lepton-number violations and a reason for mixing among charged gauge bosons—the standard modelW±and the bilepton gauge bosonsY±, as well as among the neutral non-Hermitian bileptonX0and neutral gauge bosons—theZand the newZ′. 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 andu≃𝒪(1)GeV,v≃vweak=246GeV, andω≃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.

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
P. V. Dong ◽  
V. T. N. Huyen ◽  
H. N. Long ◽  
H. V. Thuy

The mixing among gauge bosons in the 3-3-1 models with the discrete symmetries is investigated. To get tribimaximal neutrino mixing, we have to introduce sextets containing neutral scalar components with lepton numberL=1,2. Assignation of VEVs to these fields leads to the mixing of the new gauge bosons and those in the standard model. The mixing in the charged gauge bosons leads to the lepton number violating interactions of theWboson. The same situation happens in the neutral gauge boson sector.


1986 ◽  
Vol 01 (01) ◽  
pp. 57-69 ◽  
Author(s):  
JOHN ELLIS ◽  
K. ENQVIST ◽  
D.V. NANOPOULOS ◽  
F. ZWIRNER

We compile phenomenological constraints on the minimal low-energy effective theory which can be obtained from the superstring by Calabi-Yau compactification. Mixing with the single additional neutral gauge boson in this model reduces the mass of the conventional Z0, Field vacuum expectation values are constrained by the experimental upper bound on this shift. Then, requiring the sneutrino mass squared to be positive constrains the scale of supersymmetry breaking more than do lower bounds on the masses of new charged particles and of sparticles. More model-dependent constraints follow from the “naturalness” requirement that observables do not depend sensitively on input parameters. We find a preference for the second neutral gauge boson to weigh ≲320 GeV, [Formula: see text] GeV and [Formula: see text] GeV. Dynamical generation of the gauge hierarchy is possible if mt≲70 GeV, with lower values of mt being favoured.


2016 ◽  
Vol 31 (19) ◽  
pp. 1650117 ◽  
Author(s):  
Gauhar Abbas

A right–right–left extension of the Standard Model is proposed. In this model, SM gauge group [Formula: see text] is extended to [Formula: see text]. The gauge symmetries [Formula: see text], [Formula: see text] are the mirror counterparts of the [Formula: see text] and [Formula: see text], respectively. Parity is spontaneously broken when the scalar Higgs fields acquire vacuum expectation values (VEVs) in a certain pattern. Parity is restored at the scale of [Formula: see text]. The gauge sector has a unique pattern. The scalar sector of the model is optimum, elegant and unique.


2015 ◽  
Vol 25 (3) ◽  
pp. 227
Author(s):  
Hoang Ngoc Long ◽  
Lam Phu An Huy ◽  
Tran Thanh Thuy ◽  
Ly Thi Tu Tran ◽  
Vu Thi Hoang Yen

We show that the mass matrix of electrically neutral gauge bosons in the recent proposed  model based on \(\mathrm{SU}(3)_C\otimes \mathrm{SU}(3)_L\otimes \mathrm{U}(1)_X\) group with three neutrino singlets [9] has two exact eigenvalues and corresponding eigenvectors. Hence the neutral non-Hermitian gauge boson \(X^0_\mu\) is properly determined.With extra vacuum expectation values of the Higgs fields, there are mixings among charged gauge bosons \(W^\pm\) and \(Y^\pm\) as well as amongneutral gauge bosons \(Z, Z'\) and \(X^0\). From the $W$ boson decay width, we get lower bound on  scale of the model about few TeVs.


Author(s):  
Chitta Ranjan Das ◽  
Katri Huitu ◽  
Timo Kärkkäinen

Five fundamental problems—neutrino mass, baryogenesis, dark matter, inflation, strong CP problem—are solved at one stroke in a model, dubbed as “SM-A-S-H” (Standard Model-Axion-Seesaw-Higgs portal inflation) by Andreas Ringwald et. al. The Standard Model (SM) particle content is extended by three right-handed SM-singlet neutrinos $N_i$, a vector-like color triplet quark $Q$, a complex SM-singlet scalar field $\sigma$ that stabilises the Higgs potential, all of them being charged under Peccei-Quinn (PQ) $U(1)$ symmetry, the vacuum expectation value $v_\sigma\sim10^{11}$ GeV breaks the lepton number and the Peccei-Quinn symmetry simultaneously. We found that numerically SMASH model not only solves five fundamental problems but also the sixth problem “Vacuum Metastability” through the extended scalar sector and can predict approximately correct atmospheric neutrino mass splitting around 0.05 eV and the solar neutrino mass splitting around 0.009 eV.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Petr Beneš ◽  
Jiří Hošek ◽  
Adam Smetana

Abstract Higgs sector of the Standard model (SM) is replaced by quantum flavor dynamics (QFD), the gauged flavor SU(3)f symmetry with scale Λ. Anomaly freedom requires addition of three νR. The approximate QFD Schwinger-Dyson equation for the Euclidean infrared fermion self-energies Σf(p2) has the spontaneous-chiral-symmetry-breaking solutions ideal for seesaw: (1) Σf(p2) = $$ {M}_{fR}^2/p $$ M fR 2 / p where three Majorana masses MfR of νfR are of order Λ. (2) Σf(p2) = $$ {m}_f^2/p $$ m f 2 / p where three Dirac masses mf = m(0)1 + m(3)λ3 + m(8)λ8 of SM fermions are exponentially suppressed w.r.t. Λ, and degenerate for all SM fermions in f. (1) MfR break SU(3)f symmetry completely; m(3), m(8) superimpose the tiny breaking to U(1) × U(1). All flavor gluons thus acquire self-consistently the masses ∼ Λ. (2) All mf break the electroweak SU(2)L × U(1)Y to U(1)em. Symmetry partners of the composite Nambu-Goldstone bosons are the genuine Higgs particles: (1) three νR-composed Higgses χi with masses ∼ Λ. (2) Two new SM-fermion-composed Higgses h3, h8 with masses ∼ m(3), m(8), respectively. (3) The SM-like SM-fermion-composed Higgs h with mass ∼ m(0), the effective Fermi scale. Σf(p2)-dependent vertices in the electroweak Ward-Takahashi identities imply: the axial-vector ones give rise to the W and Z masses at Fermi scale. The polar-vector ones give rise to the fermion mass splitting in f. At the present exploratory stage the splitting comes out unrealistic.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Ufuk Aydemir ◽  
Tanumoy Mandal

We investigate the possibility of TeV-scale scalars as low energy remnants arising in the nonsupersymmetric SO(10) grand unification framework where the field content is minimal. We consider a scenario where the SO(10) gauge symmetry is broken into the gauge symmetry of the Standard Model (SM) through multiple stages of symmetry breaking, and a colored and hypercharged scalar χ picks a TeV-scale mass in the process. The last stage of the symmetry breaking occurs at the TeV-scale where the left-right symmetry, that is, SU(2)L⊗SU(2)R⊗U(1)B-L⊗SU(3)C, is broken into that of the SM by a singlet scalar field S of mass MS~1 TeV, which is a component of an SU(2)R-triplet scalar field, acquiring a TeV-scale vacuum expectation value. For the LHC phenomenology, we consider a scenario where S is produced via gluon-gluon fusion through loop interactions with χ and also decays to a pair of SM gauge bosons through χ in the loop. We find that the parameter space is heavily constrained from the latest LHC data. We use a multivariate analysis to estimate the LHC discovery reach of S into the diphoton channel.


2020 ◽  
Vol 35 (18) ◽  
pp. 2050153
Author(s):  
J. I. Aranda ◽  
D. Espinosa-Gómez ◽  
J. Montaño ◽  
F. Ramírez-Zavaleta ◽  
E. S. Tututi

The rare top quark decays mediated by a new neutral massive gauge boson that is predicted in models with extended gauge symmetries are studied. We focus on the processes [Formula: see text] induced at the one loop level, where [Formula: see text], by considering different extended models. It is found that, within a broad range of mass of the new neutral gauge boson, the models predict branching ratios for the decays in study that are competitive with respect to the corresponding branching ratios in the Standard Model (SM). In order to establish bound on our branching ratios, we consider the recent experimental bounds as [Formula: see text], depending on the model, which also impose restrictions on our calculation. Even in this case, the resulting branching ratios are of the same order of magnitude as that predicted by the SM. It should be noted that for the case of two models studied here, since no experimental bound exists to compare with, the results could be important, as they are, in the best of cases, two orders of magnitude larger than the predicted by the SM.


1998 ◽  
Vol 13 (23) ◽  
pp. 1865-1873 ◽  
Author(s):  
HOANG NGOC LONG

A scalar sector of the 3 3 1 model with three Higgs triplets is considered in detail. The mass spectrum, eigenstates and interactions of the Higgs and the SM gauge bosons are derived. We show that one of the neutral scalars can be identified with the standard model Higgs boson, and in the considered potential, there is no mixing between scalars having vev and those without vev.


2003 ◽  
Vol 18 (09) ◽  
pp. 1573-1586 ◽  
Author(s):  
M. B. TULLY ◽  
G. C. JOSHI

We calculate the exact tree-level scalar mass matrices resulting from symmetry breaking using the most general gauge-invariant scalar potential of the 331 model, both with and without the condition that the lepton number is conserved. Physical masses are also obtained in some cases, as well as couplings to standard and exotic gauge bosons.


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