相关论文: Constraints on the mass and mixing of Z' bosons
Comparing the theoretically predicted and measured values of the mass difference of the $B^{0}_{s}$ system, we estimate the lower bound on the mass of the $Z^{\prime}$ boson of models based on the $SU(3)_{c} \otimes SU(3)_{L} \otimes…
The high-energy lepton collider TESLA can be operated in the GigaZ mode on the Z resonance, producing a billion Z bosons per year. This will allow the measurement of the effective electroweak mixing angle to an accuracy much better than one…
Anomaly free $U(1)$ extensions of the standard model (SM) predict a new neutral gauge boson $Z'$. When the $Z'$ obtains its mass from the spontaneous breaking of the new $U(1)$ symmetry by a new complex scalar field, the model also predicts…
An electroweak model of SU(3) $\times$ U(1) gauge group is studied. {}From the group theoretical constraint, the symmetry breaking of this model to the standard model occurs at 1.7~TeV or lower. Hence the mass of the new neutral gauge boson…
We investigate the effects of extra neutral gauge bosons on the high $Q^2$ region of the $e^+p \to e^+ X$ cross section at $\sqrt{s}=300$ GeV. We found that the only models with electroweak strength coupling, typical of extended gauge…
We derive limits on a class of new physics effects that are naturally present in grand unified theories based on extended gauge groups, and in particular in $E_6$ and $SO(10)$ models. We concentrate on $i$) the effects of the mixing of new…
We review the status of precision measurements of weak neutral current interactions, mediated by the $Z^0$ boson, at $Q^2\ll M_Z^2$. They can be used to extract values for the weak mixing angle $\sin^2\theta_W$, a fundamental parameter of…
New neutral vector bosons $Z'$ decaying to charged gauge boson pairs $W^+W^-$ are predicted in many scenarios of new physics, including models with an extended gauge sector such as $E_6$, left-right symmetric $Z^\prime_{\rm LRS}$ and the…
We calculate the gauge couplings in the dual standard model. These values are consistent with an associated GeV mass scale, and predict the weak mixing angle to be ${\sin^2 \theta_w} (M_Z) \sim 0.22$.
A general electroweak scale $Z'$ is applied in a supersymmetric SU(6)$\timesSU(2)_h$ grand unification model, to have a $\Z_6$ for the hexality. We briefly show that there cannot exist any baryonic U(1)$'_B$ in any subgroup of E$_6$. Any…
This work is devoted for gauge boson sector of the recently proposed model based on SU(3)_C X SU(3)_L X U(1)_X group with minimal content of leptons and Higgses. The limits on the masses of the bilepton gauge bosons and on the mixing angle…
Many models beyond the Standard Electroweak Theory, top-down or bottom-up, contain extensions of the gauge symmetry group by extra U(1)' factors which can be understood or treated as subgroups of E(6). A brief overview of such models is…
We review the status of heavy neutral gauge bosons, Z', with emphasis on constraints that arise in supersymmetric models, especially those motivated from superstring compactifications. We first summarize the current phenomenological…
We explore some more consequences of the $SU(3)_L\otimes U(1)_N$ electroweak model with right-handed neutrinos. By introducing the $Z - Z'$ mixing angle $\phi$, the {\it exact} physical eigenstates for neutral gauge bosons are obtained.…
We obtain mass limits on the extra neutral gauge boson which is predicted in a model with hidden gauge symmetry and dynamical breaking of the electroweak symmetry by a top quark condensate. For typical model assumptions, present LEP data…
Several constructions, of stringy origins or not, generate abelian gauge extensions of the Standard Model (SM). Even if the particles of the SM are not charged under this extra $U'(1)$, one cannot avoid the presence of a kinetic mixing…
The study of electroweak boson pair production provides a powerful test of the spontaneously broken gauge symmetry of the Standard Model (SM) and can be used to search for new phenomena beyond the SM. Extra neutral vector bosons $Z'$…
A model of a light $Z'$ boson is constructed and phenomenological bounds are derived. This $Z'$ boson arises from a very simple extension to the Standard Model, and it is constrained to be light because the vacuum expectation values which…
We study $Z'$ phenomenology at hadron colliders in an $U(1)'$ extended MSSM. We choose a $U(1)'$ model with a secluded sector, where the tension between the electroweak scale and developing a large enough mass for $Z'$ is resolved by…
We present the one-loop radiative corrections to the muon decay in U(1)$_z$ extensions of the standard model. We compute the mass of the $W$ boson using those corrections and compare it to an approximation of the complete one-loop…