Associated production of the $Z$ boson with a pair of top quarks in the left-right twin Higgs model

Abstract

In the context of the left-right twin Higgs (LRTH) model, we first examine the effects on the $Zt\bar{t}$ production at the ILC and LHC. Our results show that the cross-sections can be significantly deviated from the standard model predictions and thus provide a good probe for the LRTH model. We also estimate the new production channel, $Zt\bar{T}$ or $Z\bar{t}T$ production, at the LHC. Compared with $Zt\bar{t}$ production, we find that the $Zt\bar{T}$ production can have a sizable production rate when the scale $f$ is not too high. Considering the dominant decay mode $T\to {\varphi }^{+}b\to tb\bar{b}$, we find that $Zt\bar{T}$ final state has less background than $Zt\bar{t}$ production and may likely be observable at the LHC.

Comments: Final version to appear in EPL