Hyperon-nucleon interaction and meson exchange

Abstract

We present first results of our general program which is to construct meson-exchange potentials for hadronic systems involving strange particles, i.e. for KN and ΛN. We proceed along the same guidelines which have been successfully applied in deriving the (latest version of the) Bonn NN potential, namely to keep the important recoil and nonlocal structure and to use a comprehensive set of diagrams without introducing any fictitious contribution. For KN we show that single vector-meson (ω, ϱ) exchange already provides a fair description of the data except for the isospin-1 P 3 2 wave. This partial wave is remarkably improved by adding a specific higher-order process involving ΔK intermediate states. For the ΛN system we demonstrate the inadequacy of a nonrelativistic treatment of the ΛN interaction and point to the strong interplay between K and K ★-exchange in the tensor channel, which is even stronger than for π- and ϱ-exchange in the NN system.