Measurement of differential cross section and polarization in the backward peak of the reactions π- + p → Λ + K0 and π- + p → Λ + K*(890) at 8 GeV/c

Differential cross sections and polarizations have been measured for the backward peaks in the reactions π-p → ΛK0 and π-p → ΛK*(890) at 8 GeV/c. The experiment was performed with a liquid hydrogen target at the Ω spectrometer. The cross sections for u' > -2 (GeV/c)2 are 0.27 +- 0.03 μb for π-p → ΛK0 and 0.55 +- 0.07 μb for π-p → ΛK*0. Large positive Λ polarization was observed in both reactions for u' > -0.5 (GeV/c)2. The dominant production mechanism was found to be unnatural baryon exchange. (Auth.)