Spin effects in neutralino production in e+e- annihilation with polarized beams

We study the process e+e-→χ10χ20 and the subsequent decay χ20→χ10l+l- with polarized beams, including the complete spin correlations of χ20. We present numerical results for the lepton energy and angular distributions, and for the distribution of the opening angle between the leptons for √s = 500 GeV. The effects of spin correlations are important in the lepton angular distribution, especially for gaugino-like neutralinos. The opening angle distribution is particularly suitable for distinguishing between higgsino- and gaugino-like neutralinos. The polarized cross sections and lepton angular distributions are very sensitive to the mixing of the neutralinos. (author)