Measurement ofΛ0Polarization in InclusiveΛ0Production at 28.5 GeV/c

${\Lambda }^{\circ }$ polarization in inclusive production by protons on iridium has been measured at 28.5 GeV/c over the region $0.55 \mathrm{GeV}/c<~P_{\perp }<~1.6 \mathrm{GeV}/c$. The polarization rises from (-12.6±5.5)% at 0.55 GeV/c to (-33.4±4.6)% at 1.6 GeV/c. Significant differences from previous measurements at other energies with different targets are observed, particularly at low $P_{\perp }$.