Polarization in inclusiveΛandΛ¯production at largepT

A study of the inclusive polarization of $\Lambda$ hyperons produced by 400-GeV/c protons incident on nuclear targets has been performed at Fermilab. The polarization P of the $\Lambda$ has been mapped over a large range of $x_F$ and $p_T$ to good precision for $p_T$ up to 3.8 GeV/c. The magnitude of the polarization at fixed $x_F$ rises with $p_T$ to a plateau at about 1 GeV/c, and the size of the plateau increases monotonically with $x_F$. The $\overline{\Lambda }$ were found to be unpolarized for $p_T<2.4\mathrm{}$ GeV/c. A target-nucleus dependence for the $\Lambda$ polarization has been observed.