Production and polarization of the $\Lambda$ and $\bar{\Lambda}$ hyperons in DIS at COMPASS

$\Lambda$ and $\bar{\Lambda}$ hyperons were produced at the COMPASS experiment at CERN, using Deep-Inelastic Scattering (DIS) of 160 GeV/c polarized muons on a longitudinally polarized target. The study of $\Lambda$ and $\bar{\Lambda}$ hyperons in DIS is important for the understanding of the nucleon structure, the mechanisms of hyperon production and the hyperon spin structure. In particular, it may provide valuable information on the unpolarized strange quark distributions $s(x)$ and $\bar{s}(x)$ in the nucleon. The data sample contains about 70 000 $\Lambda$ and 42 000 $\bar{\Lambda}$ . Large and comparable statistics on both $\Lambda$ and $\bar{\Lambda}$ hyperons is a distinct feature of the COMPASS experiment. Preliminary results on polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons and yields of heavy hyperons in DIS are presented.