Elastic Scattering of Lambda Hyperons from Protons

The $\Lambda$-proton elastic scattering cross section has been measured to be 20±5 mb. This value represents an average over the momentum interval 150-1500 MeV/c. It is based on 26 events observed in a propane bubble chamber. The $\Lambda$ hyperons were produced by the interactions of 1.15-BeV/c $K^{-}$ mesons in the propane.