One-loop QCD and electroweak corrections tott¯Z0production at ane+e−linear collider

Abstract

We study the impact of the full $\mathcal{O}({\ensuremath{\alpha}}_{s})$ QCD and $\mathcal{O}({\ensuremath{\alpha}}_{\mathrm{ew}})$ electroweak (EW) radiative corrections to the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}t\overline{t}{Z}^{0}$ process in the standard model, and investigate the dependence of the lowest-order (LO), one-loop QCD and EW corrected cross sections on colliding energy $\sqrt{s}$. The LO, QCD and EW corrected spectrums of the invariant mass of $t\overline{t}$ pair and the distributions of the transverse momenta of final top quark and ${Z}^{0}$ boson are presented. The numerical results show that the one-loop QCD correction enhances the LO cross section, but the EW one-loop correction generally suppresses the LO cross section with our chosen parameters. In the case of ${m}_{H}=120\text{ }\text{ }\mathrm{GeV}$, the QCD relative corrections can reach 43.16% when $\sqrt{s}=500\text{ }\text{ }\mathrm{GeV}$, while the EW relative corrections have the values of $\ensuremath{-}9.24%$, $\ensuremath{-}4.36%$ and $\ensuremath{-}5.81%$, when $\sqrt{s}=500\text{ }\text{ }\mathrm{GeV}$, 800 GeV, 1.2 TeV, respectively.