A meson-exchange model for the antihyperon-hyperon production

Abstract

A meson-exchange model for strangeness production processes p p→ YY ( Y = Λ, Σ) is presented, which is based on a full coupled-channel treatment. The transition interactions are given by K- and K ∗-meson exchange. The elastic part of the p p and Y Y interactions has been derived from a one-boson-exchange version of the Bonn NN potential and a corresponding extension to the hyperon-nucleon case whereas the annihilation part is taken into account by introducing phenomenological optical potentials. Results for cross sections, polarizations, depolarization and spin correlation parameters are presented for the reactions p p → ΛΣ 0, Σ 0Λ as well as p → Σ ±Σ ± , Σ 0Σ 0 . As in p →- Λ , tensor and spin-triplet d p p → ΣΣ but is somewhat reduced in p → ΛΣ 0, Σ 0Λ . Although Σ −Σ − cannot be reached from p p by a one step transition the corresponding cross section is only slightly smaller than that for \\ ̄ gS +Σ + . For pp → ΛΣ 0, Σ 0Λ, the results are compared to those derived from different transition interactions based on (i) K-exchange only and (ii) the constituent quark model ( 3S 1 version). Predictions are made for the Y Y → Y Y cross sections.