ar X iv : h ep - p h / 96 04 32 8 v 1 1 6 A pr 1 99 6 Top Quark Polarization in Polarized e + e − Annihilation near Threshold ∗

Top quark polarization in e + e − annihilation into t ¯ t is calculated for linearly polarized beams. The Green function formalism is applied to this reaction near threshold. The Lippmann–Schwinger equations for the S-wave and P-wave Green functions are solved numerically for the QCD chromostatic potential given by the two-loop formula for large momentum transfer and Richardson's ansatz for intermediate and small momenta. S-P –wave interference contributes to all components of the top quark polarization vector. Rescattering of the decay products is considered. The mean values nℓ of the charged lepton four-momentum projections on appropriately chosen directions n in semileptonic top decays are proposed as experimentally observable quantities sensitive to top quark polarization. The results for nℓ are obtained including S-P –wave interference and rescattering of the decay products. It is demonstrated that for the longitudinally polarized electron beam a highly polarized sample of top quarks can be produced.