Polarization ofΞ0andΛHyperons Produced by 400-GeV/cProtons

The polarization of ${\Xi }^0$ and $\Lambda$ hyperons produced by 400-GeV protons interacting with a beryllium target has been measured in the projectile fragmentation region. The ${\Xi }^0$ polarization agrees in sign, magnitude, and kinematic behavior with that of $\Lambda$. The target dependence of these ${\Xi }^0$ and $\Lambda$ polarizations was also investigated with use of Cu and Pb targets.