Production of Λ hyperons and KS0 mesons in annihilation of antiprotons on 4He nuclei at 600 MeV/c

Λ-hyperon and KS0-meson production cross sections in antiproton annihilation in 4He at 600 MeV/c have been measured. An anomalously-high yield of Λ is observed which is comparable to that of KS0:R=σ(Λ)/σ(K)=0.94±0.19. It was shown that the difference in the Λ and KS0 rapidity distributions may be explained by different mechanisms of production of these particles: KS0 mesons are produced mainly in p-bar annihilation on single nucleons from the nucleus, and Λ hyperons in secondary processes of rescattering of the annihilation mesons