Polarized Λ0 production at KEK

We have measured the polarization of Λ0 hyperons produced inclusively by 12 GeV protons on tungsten at KEK. For moderate xF (0.2≳xF≳0.7), the polarization is nearly independent of xF and increases roughly linearly with pT. As xF increases beyond 0.7, however, the polarization shows a significant xF dependence. Some preliminary data were taken on copper and beryllium targets. A future project on Σ0 polarization at KEK is indicated.