Spin correlations in top-quark pair production at e+e− colliders

We show that top-quark pairs are produced in an essentially unique spin configuration in polarized e+e− colliders at all energies above the threshold region. Since the directions of the electroweak decay products of polarized top-quarks are strongly correlated to the top-quark spin axis, this unique spin configuration leads to a distinctive topology for top-quark pair events which can be used to constrain anomalous couplings to the top-quark. A significant interference effect between the longitudinal and transverse W-bosons in the decay of polarized top-quarks is also discussed. These results are obtained at leading order in perturbation theory but radiative corrections are expected to be small.