Production and polarization of the Λ and hyperons in DIS at COMPASS

Λ and 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 Λ and hyperon 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 in the nucleon. The data sample contains about 70 000 Λ and 42 000 . Large and comparable statistics on both Λ and hyperons is a distinct feature of the COMPASS experiment. Preliminary results on polarization of Λ and hyperons and yields of heavy hyperons in DIS are presented.