Experimental study of the reaction<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mi>p</mml:mi><mml:mo>→</mml:mo><mml:mi>Λ</mml:mi><mml:mrow><mml:msup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>at beam momenta between 930 and 1130 MeV/<i>c</i>

We have used an optical spark-chamber spectrometer to perform a systematic study of the reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}\ensuremath{\Lambda}{K}^{0}$ at beam momenta between 930 and 1130 MeV/c. The cross section, angular distribution, and $\ensuremath{\Lambda}$ polarization have been measured. We present our complete data from a sample of 11 400 events along with Legendre polynomial coefficients for the angular distributions. No striking cross-section enhancement at $\ensuremath{\Sigma}K$ threshold is observed, but there is evidence for a small cusp effect. A simple model which takes account of the $\ensuremath{\Sigma}K$ channel provides a good fit to our data.