O(αs) spin-spin correlations for top and bottom quark production in e+e− annihilation

Abstract

We present the full O(alpha_s) longitudinal spin-spin correlations for\nheavy-quark pair production at e+ e- high-energy colliders in closed analytical\nform. In such reactions, quark and antiquark have strongly correlated spins,\nand the longitudinal components are dominant. For the explicit computation of\nthe QCD bremsstrahlung contributions, new phase-space integrals are derived.\nExplicit numerical estimates are given for t t_bar and b b_bar production.\nAround the Z-peak, QCD one-loop corrections depolarize the spin-spin asymmetry\nfor bottom quark pairs by approximately -4%. For top pair production, we find\nat 350GeV a 0.6% increased polarization over a value of 0.4 in the longitudinal\ncorrelation. For more than 1 TeV the O(alpha_s) corrections enhance\ndepolarization to -2% in the top-pair case.\n