\nu \to t \bar t \nu \bar \nu$ by adding these dimension-six operators to the SM Lagrangian, and evaluate possible deviation from the SM prediction under the constraint from perturbative unitarity[@pwu] and current experimental data[@pdg]. This process $e^-e^+ \to W^-W^+ \nu \bar \nu \to t \bar t \nu \bar \nu$ has at first been studied by Yuan[@yuan], Gintner and Godfrey[@godfrey] in the SM, and its QCD correction has been studied by Godfrey and Zhu[@godfrey2]. Larios et al. have investigated the same process in the context of the SM without the Higgs boson, instead including the dimension-five operators $W^-W^+ \bar t t$ and $W^-_\mu W^+_\nu \bar t \sigma^{\mu\nu} t$[@larios]. In the present paper, we keep the Higgs boson mass to be the electroweak scale, and classify the non-standard interaction between the Higgs boson and the top quark in terms of the dimension-six operators with setting the cutoff scale to be TeV scales. We find that the effect of the dimension-six operators with the cutoff scale to be a TeV region can enhance the cross section significantly especially for relatively large Higgs boson masses, so that the effect should be detectable at the ILC.

This paper is organized as follows. In Sec. 