Atomic parity violation in cesium and implications for the 3-3-1 models

The parity violation in cesium atom is analysed in the framework of the models based on the SU(3)C×SU(3)L×U(1)N gauge group. It is shown that in the minimal version, the main contribution to a deviation of weak charge ΔQW 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.