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 e nergy 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 produ ction reactions (K) over barN-->Lambda pi (0) and omegap-->K(+)Lambda was p erformed and it was found that most of hyperons (about 70%) are produced vi a the reaction (K) over barN-->YX, while the remaining ones come mainly fro m the omegaN-->KYX process, in agreement with the predictions of the cascad e models, The (K) over barN --> Lambda pi (0) and the omegap-->K(+)Lambda c ross 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, re presents the first experimental determination. (C) 2001 Elsevier Science B. V. All rights reserved.