1996/04/16 by R. Harlander, M. Jezabek, J. H. Kuehn +1
Physics and Astronomy · #hep-ph
published as Z.Phys. C73 (1997) 477-494 · LaTeX2e, 46 pages, 18 postscript figures included. Uses epsf. The complete paper, including figures, is also available via anonymous ftp at ftp://www-ttp.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints
arxiv created 1996/04/16 · arxiv updated 2009/11/30
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 ⟨ n ℓ ⟩ 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 ⟨ n ℓ ⟩ 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.