Longitudinal polarization of $\Lambda$ and $\bar \Lambda$ hyperons in   deep-inelastic scattering at COMPASS
  The production of Lambda and Lambda-bar hyperons by polarized muons of 160 GeV/c on a polarized 6LiD target has been studied using the COMPASS spectrometer. First preliminary results on the longitudinal polarization of Lambda and Lambda-bar hyperons produced in the deep-inelastic scattering will be presented for 2002 data set. 
V.Yu. Alexakhin (on behalf of the COMPASS Collaboration)