Bounds of the mass ofZ′and the neutral mixing angles in generalSU(2)

Abstract

We consider phenomenological constraints on the mass M Z Ј and the mixing angles R and of the neutral sector in general SU(2) L ϫSU(2) R ϫU(1) models using electroweak data. The analysis of the neutral sector has the advantage that it has relatively fewer parameters compared to the charged sector since the Cabibbo-Kobayashi-Maskawa matrix elements in the right-handed sector are not involved. We consider the theoretical relations between the gauge boson masses and the mixing angles. We combine the precision electroweak data from CERN LEP I and the low-energy neutral-current experimental data to constrain the parameters in the model. It turns out that M Z Ј Ͼ430 GeV, Ϫ0.00040ϽϽ0.0037, with little constraint on R . Using these constraints, we compare (e ϩ e Ϫ → ϩ Ϫ ), (e ϩ e Ϫ →bb ), and A FB l with the experimental data at LEP II.

CPviolating dimuon charge asymmetry in general left-right models

“…Involving the triplet Higgs field Á L;R to break the additional SUð2Þ R symmetry, the lepton-number-violating Yukawa terms are introduced and the seesaw mechanism for light neutrino masses can be exploited in the LRM. The scale of the masses of the new gauge bosons in the LRM is constrained by direct searches and indirect analysis [8][9][10][11], and we will discuss the constraints on the model in further detail. This paper is organized as follows.…”

Combining left-right and quark-lepton symmetries in 5D

“…We find that in the LR limit one requires w R > 5.2 TeV (w R > 6.6 TeV) at the 95% (90%) confidence level, which leads to M Z ′ > 2.8 TeV (M Z ′ > 3.5 TeV). Note that we fit to more precision electroweak parameters than previous works using neutral currents to bounds LR breaking scales and thus, to the best of our knowledge, this is the strongest bound on w R yet obtained in the literature (for previous bounds see [20,21]). In the QL limit, it is necessary that w l > 1.5 TeV (w l > 1.9 TeV) and M Z ′ > 1.5 TeV (M Z ′ > 1.9 TeV).…”

Global analysis of generalSU(2)×SU(2)×U(1)models wit

“…In the symmetric left-right model (where the couplings of the W are of the same strength as those of the W ), Polak and Zralek obtained the constraints on parameters from the Z-pole data [20] and low energy data [21], separately. While for the non-symmetric case, Chay, Lee and Nam [22] considered phenomenological constraints on three parameters: the mass of the Z , the mixing anglesφ (the analog of the Weinberg angle in the breaking of SU (2) R × U (1) X → U (1) Y ) and the Z-Z mixing angle ξ, by combining the precision electroweak data from LEP I (through 1 , 2 , 3 ) and the low-energy neutral-current experimental data. For the non-symmetric case, the combined bounds at the 95% confidence level are 0.0028 < ξ < 0.0065 and M Z ≥ 400 GeV for allφ, while for the symmetric case, a more severe bound M Z ≥ 1.6 TeV is obtained.…”