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Register a new userAtomic parity violation in cesium and implications for the 3 - 3 - 1 models
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The parity violation in cesium atom is analysed in the framework of the models based on the SU(3)_C X SU(3)_L X U(1)_N gauge group. It is shown that in the minimal version, the main contribution to a deviation of weak charge Delta Q_W due to direct Z exchange is negative. New data on parity violation in the cesium atom seems not favour to the minimal version, while it gets a positive value in the version with right-handed neutrinos. We obtain a bound on the $Z$ mass at a range from 1.4 TeV to 2.6 TeV. The allowed regions for the Z-Z$mixing angle are also derived.
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We have witnessed a persistent puzzling anomaly in the muon magnetic moment that cannot be accounted for in the Standard Model even considering the large hadronic uncertainties. A new measurement is forthcoming, and it might give rise to a $5sigma$ claim for physics beyond the Standard Model. Motivated by it, we explore the implications of this new result to five models based on the $SU(3)_C times SU(3)_L times U(1)_N$ gauge symmetry and put our conclusions into perspective with LHC bounds. We show that previous conclusions found in the context of such models change if there are more than one heavy particle running in the loop. Moreover, having in mind the projected precision aimed by the g-2 experiment at FERMILAB, we place lower mass bounds on the particles that contribute to muon anomalous magnetic moment assuming the anomaly is resolved otherwise. Lastly, we discuss how these models could accommodate such anomaly in agreement with existing bounds.
The recent experimental data of the weak charges of Cesium and proton is analyzed in the framework of the models based on the $mbox{SU}(3)_Ctimes mbox{SU}(3)_L times mbox{U}(1)_X$ (3-3-1) gauge group, including the 3-3-1 model with CKS mechanism (3-3-1CKS) and the general 3-3-1 models with arbitrary $beta$ (3-3-1$beta$) with three Higgs triplets. We will show that at the TeV scale, the mixing among neutral gauge bosons plays significant effect. Within the present values of the weak charges of Cesium and proton we get the lowest mass bound of the extra heavy neutral gauge boson to be 1.27 TeV. The results derived from the weak charge data, perturbative limit of Yukawa coupling of the top quark, and the relevant Landau poles favor the models with $beta =pm 1/sqrt{3}$ and $beta = 0$ while ruling out the ones with $beta= pm sqrt{3}$. In addition, there are some hints showing that in the 3-3-1 models, the third quark family should be treated differently from the first twos.
We propose two 3-3-1 models (with either neutral fermions or right-handed neutrinos) based on S_3 flavor symmetry responsible for fermion masses and mixings. The models can be distinguished upon the new charge embedding (mathcal{L}) relevant to lepton number. The neutrino small masses can be given via a cooperation of type I and type II seesaw mechanisms. The latest data on neutrino oscillation can be fitted provided that the flavor symmetry is broken via two different directions S_3 rightarrow Z_2 and S_3 rightarrow Z_3 (or equivalently in the sequel S_3 rightarrow Z_2 rightarrow Identity), in which the second direction is due to a scalar triplet and another antisextet as small perturbation. In addition, breaking of either lepton parity in the model with neutral fermions or lepton number in the model with right-handed neutrinos must be happened due to the mathcal{L}-violating scalar potential. The TeV seesaw scale can be naturally recognized in the former model. The degenerate masses of fermion pairs (mu, tau), (c, t) and (s, b) are respectively separated due to the S_3 rightarrow Z_3 breaking.
The stellar energy-loss rates $mathcal{Q}$ due to the production of neutrino pair in the framework of 3-3-1 models are presented. The energy loss rate $mathcal{Q}$ is evaluated for different values of $beta=pmfr{1}{sqrt{3}},pmfr{2}{sqrt{3}},pmsqrt{3}$ in which $beta$ is a parameter used to define the charge operator in the 3-3-1 models. The correction to the rate which is compared with that of the Standard Model ($de mathcal{Q}$) is also evaluated. We show that the correction does not exceed 14% and %is gets the highest with $beta=-sqrt{3}$. The contribution of dipole moment to the energy loss rate is small compared to the contribution of new natural gauge boson $Z$ and this sets constraints for the mass of Z $m_{Z} leq 4000$ GeV. This mass range is within the searching range for $Z$ boson at LHC.
We present a detailed discussion of the triplet anti-triplet symmetry in 3-3-1 models. The full set of conditions to realize this symmetry is provided, which includes in particular the requirement that the two vacuum expectation values of the two scalar triplets responsible for making the W and Z bosons massive must be interchanged. We apply this new understanding to the calculation of processes that have a Z-Z mixing.
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