Evidence of elementary processes for hyperon production in low-energy antiproton annihilation on Xenon nuclei

Hyperon production mechanisms in antiproton annihilation on nuclei at low energy were investigated by using 7.8 x 10(5) annihilations events in the Xe bubble chamber DIANA at P ((p)) over bar less than or equal to 0.9 GeV/c. The full kinematical reconstruction of the two-body secondary hyperon production reactions (K) over barN-->Lambda pi (0) and omegap-->K(+)Lambda was performed and it was found that most of hyperons (about 70%) are produced via the reaction (K) over barN-->YX, while the remaining ones come mainly from the omegaN-->KYX process, in agreement with the predictions of the cascade models, The (K) over barN --> Lambda pi (0) and the omegap-->K(+)Lambda cross sections were also estimated as further consistency check. The latter, sigma (K+Lambda)(omega) = (0.47 +/- 0.25) mb at [P-omega] = 0.42 GeV/c, represents the first experimental determination. (C) 2001 Elsevier Science B.V. All rights reserved.