PROBING NEW GAUGE BOSON Z′ FROM THE LEFT–RIGHT TWIN HIGGS MODEL AT HIGH-ENERGY e+e- COLLIDERS.

The left–right twin Higgs (LRTH) model predicts the existence of the new neutral gauge boson Z′. In this paper, we calculate the contributions of this new particle to the processes e+e-→l+l-, $b\bar b$ and $c\bar c$ and study the possibility of detecting this new particle via these processes in the future high-energy linear e+e- collider (LC) experiments with $\sqrt{s}=500~{\rm GeV}$ and £int = 340 fb-1, both for unpolarized and polarized beams. We find that the new gauge boson Z′ is most sensitive to the process $e^{+}e^{-}\rightarrow c\bar{c}$ with suitably polarized beams. As long as MZ′ ≤ 1.9 TeV, the absolute value of the relative correction parameter is larger than 5%. We calculate the forward–backward asymmetries for the process $e^{+}e^{-}\rightarrow f\bar{f}$, the results show that the possible signals of Z′ might be detected via measuring the deviations of AFB from its SM prediction for $\sqrt{s}\simeq M_{Z'}$. Bounds on Z′ masses are also estimated within 95% confidence level. From our analysis, we conclude that the new gauge boson is most sensitive to the process F>$e^+e^-\to c\bar c$ and its virtual effects are most easy to be observed via this process in the future LC experiments. [ABSTRACT FROM AUTHOR]