Beam polarization and spin correlation effects in chargino production and decay

We study chargino production $e^+ e^- -> \chi^+_1 \chi^-_1$ and the subsequent leptonic decay $\chi^-_1\to \chi^0_1 e^- \nu_e$ including the complete spin correlations between production and decay. We work out the advantages of polarizing the $e^+$ and $e^-$ beams. We study in detail the polarized cross sections, the angular distribution and the forward--backward asymmetry of the decay electron. They can be used to determine the sneutrino mass $m_{\tilde{\nu}_e}$