Related papers: Neutral currents in reduced minimal 3-3-1 model
We tested several models in which the Standard Model (SM) gauge group is extended by an additional U(1) gauge symmetry, against available electroweak precision data to impose limits on the mass of the neutral Z' boson, M_Z', predicted in…
We consider flavor changing neutral current effects coming from the $Z'$ exchange in 3-3-1 models. We show that the mass of this extra neutral vector boson may be less than 2 TeV and discuss the problem of quark family discrimination.
Flavor changing neutral currents coming from a new non-universal neutral Gauge-Boson and from the non-unitary quark mixing matrix for the $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ model with right handed neutrinos are studied. By imposing as…
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…
The observed sign of a deviation from the $e$-$\mu$ universality in tau decays suggests family gauge bosons with an inverted mass hierarchy. Under the constraints from the observed $K^0$-$\bar{K}^0$ and $D^0$-$\bar{D}^0$ mixing, we…
We present a 3-3-1 model as a subgroup of SU(4)PS X SU(4)L+R gauge symmetry with symmetry-breaking pattern SU(4)->SU(3) X U(1) for both SU(4) groups. A Pleitez-Frampton type of 3C-3L-1X model is obtained with charged heavy leptons and…
We study theoretical and experimental constraints on electroweak theories including a new color-singlet and electrically-neutral gauge boson. We first note that the electric charges of the observed fermions imply that any such Z' boson may…
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…
We consider phenomenological constraints on the mass $M_{Z^{\prime}}$ and the two mixing angles $\theta_R$ and $\xi$ of the neutral sector in a very general class of $SU(2)_L \times SU(2)_R \times U(1)$ models using electroweak data. We do…
We propose a new and realistic 3-3-1 model with the minimal lepton and scalar contents, named the simple 3-3-1 model. The scalar sector contains two new heavy Higgs bosons, one neutral H and another singly-charged H^\pm, besides the…
We show that in the minimal 3-3-1 model the flavor changing neutral currents (FCNCs) do not impose necessarily strong constraints on the mass of the $Z^\prime$ of the model if we also consider the neutral scalar contributions to such…
Indirect precision data are used to constrain the masses of possible extra Z^prime bosons and their mixings with the ordinary Z. We study a variety of Z^prime bosons as they appear in E_6 and left-right unification models, the sequential Z…
Meson and anti-meson mixing processes constitute an important source of constraints on models that give tree level contributions to flavor violating neutral processes. In electroweak $ \text{SU}(3)_\text{L} \times \text{U}(1)_N $ models,…
A U(3) family gauge boson model is investigated based on U(3)$\times$[U(1)]$^3$ gauge symmetry. In this model, of nine U(3) family gauge bosons $A_i^{\ j}$, those with $i=j$ are considerable heavy compared with those with $i \neq j$, so…
A simple extension of the Standard Model (SM), based on the gauge group $SU(3)_C\otimes SU(3)_L\otimes U(1)_Y$ with $Y$ being the hypercharge, is considered. We show that, by imposing an approximate global $SU(2)_L\times SU(2)_R$ custodial…
We propose a model based on SU(3) family symmetry which leads to a successful description of quark and lepton masses and mixing angles including approximate bi-maximal mixing in the neutrino sector suitable for the LOW or quasi-vacuum solar…
We consider a model in which the third family fermions are subjected to an SU(2) interaction different from the first two family fermions. Constrained by the Z-pole data, the heavy gauge boson mass is bounded from below to be about 1.7 TeV…
The Large Hadron Collider will restart with higher energy and luminosity in 2015. This achievement opens the possibility of discovering new phenomena hardly described by the Standard Model, that is based on two neutral gauge bosons: the…
We examine direct limits on masses of the extra neutral gauge bosons in the SU(4)_L \times U(1)_X model with a little Higgs mechanism confronted with the LHC data, especially by embedding anomaly-free set of fermions. There exist two extra…
We analyze the effect of flavor changing neutral currents within 331 models. In particular, we concentrate in the so-called "economical" models, which have a minimal scalar sector. Taking into account the experimental measurements of…