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_{\tilde{\nu}_{l L}} = m_W^2 \cos 2\ga $(l=e, \mu)$. In addition, within the above effective limit, there exists degeneracy among sneutrinos in each multiplet: $m^2_{\tilde{\nu}_{l L}} = m^2_{\tilde{\nu}_{l R}}$. In contradiction to the MSSM, the squark mass splittings are different for each generation and not to be m_W^2 \cos 2\ga.Comment: 34 pages, 2 figures, Revised version in which D-term and F-term contributions are slightly change

Stability of the Scalar Potential and Symmetry Breaking in the Economical 3-3-1 Model

A detailed study of the criteria for stability of the scalar potential and the proper electroweak symmetry breaking pattern in the economical 3-3-1 model, is presented. For the analysis we use, and improve, a method previously developed to study the scalar potential in the two-Higgs-doublet extension of the standard model. A new theorem related to the stability of the potential is stated. As a consequence of this study, the consistency of the economical 3-3-1 model emerges.Comment: to be published in EPJ C, 13 page

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$|\sin \theta| < 0.043$.Comment: replace with version to appear in Phys. Lett.

One photon and two photon process in photo-decomposition of germanium oxygen deficient centres

UV photon-induced transformation of germanium oxygen deficient centres (GODC) in germanium-doped silica glass have been studied using photocurrent measurements, absorption and fluorescence bleaching. It has been identified that the photocurrent are generated via a two photon effect. Evidence have been found suggesting that the UV photon-induced destruction of GODCs is achieved via two reaction pathways, a single photon pathway and a two photon pathway. The process is discussed

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 $\chi$ and its supersymmetric counterpart $\chi^\prime$. 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.Comment: 33 page

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.Comment: 33 pages, 1 figur

Scalar Potential Without Cubic Term in 3-3-1 Models Without Exotic Electric Charges

A detailed study of the criteria for stability of the scalar potential, and the proper electroweak symmetry breaking pattern in some 3-3-1 models without exotic electric charges is presented. In this paper we concentrate in a scalar sector with three Higgs scalar triplets, with a potential that does not include the cubic term, due to the presence of a discrete symmetry. For the analysis we use, and improve, a method previously developed to study the scalar potential in the two-Higgs-doublet extension of the standard model. Our main result is to show the consistency of those 3-3-1 models without exotic electric charges.Comment: 19 page

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.Comment: 20 pages, revised versio

A detailed QCD analysis of twist-3 effects in DVCS observables

In this paper I present a detailed QCD analysis of twist-3 effects in the Wandzura-Wilczek (WW) approximation in deeply virtual Compton scattering (DVCS) observables for various kinematical settings, representing the HERA, HERMES, CLAS and the planned EIC (electron-ion-collider) experiments. I find that the twist-3 effects in the WW approximation are almost always negligible at collider energies but can be large for low Q^2 and smaller x_bj in observables for the lower energy, fixed target experiments directly sensitive to the real part of DVCS amplitudes like the charge asymmetry (CA). Conclusions are then drawn about the reliability of extracting twist-2 generalized parton distributions (GPDs) from experimental data and a first, phenomenological, parameterization of the LO and NLO twist-2 GPD $H$, describing all the currently available DVCS data within the experimental errors is given.Comment: 18 pages, 21 figures, uses Revtex4, final version to be published in PRD, minor revisions due to referee suggestion

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.Comment: 20 pages, revised versio