O(αs) QCD corrections to spin correlations in the e-e+ → tt process at the NLC

Using a generic spin basis, we present a general formalism of one-loop radiative corrections to the spin correlations in the top quark pair production at the Next Linear Collider, and calculate the O(alpha(s)) QCD corrections under the soft gluon approximation. We find that: (a) in off-diagonal basis, the O(alpha(s)) QCD corrections to e(L)(-)e(+) (e(R)(-)e(+)) scattering process increase the differential cross sections of the dominant spin component t(up arrow)(t) over bar(down arrow) (t(down arrow)(t) over bar(up arrow)) by similar to 30% and similar to (0.1% - 3%) depending on the scattering angle for root s = 400 GeV and 1 TeV, respectively; (b) in off-diagonal basis (helicity basis), the dominant spin component makes up 99.8% (similar to 53%) of the total cross section at both tree and one-loop level for root s = 400 GeV, and the off-diagonal basis therefore remains to be the optimal spin basis after the inclusion of O(alpha(s)) QCD corrections. (C) 1999 Elsevier Science B.V. All rights reserved.