Die Kaonproduktion in der Pion-Nukleon Streuung in einem Mesonaustauschmodell mit gekoppelten Kanälen

In the present work a meson theoretical model for the production of kaons in the pion-nudeon interaction is developed. The study is done in a coupled channelsframework where the channels $\pi$N, K$\Lambda$, K$\Sigma$ and KY*(1385) are taken into account. The interactions in the various channels and the transition interactions are based on single meson and baryon exchange diagrams. Coupling constants are taken from SU(3) symmetry relations. Form factor parameters are deduced from previous investigations of other hadronic reactions by the Bonn-Jülich group. For the interaction in the initial7r N state a phenomenological separable model is employed. This is necessitated by the complexity of the dynamics in the energy range relevant for kaon production, making a microscopic description practicallyinfeasible. Our model for kaon production gives the correct magnitude of the cross sections for the reactions $\pi^{-}p \rightarrow K^{0} \Lambda , \pi^{+}p \rightarrow K^{+} \Sigma^{+}, \pi^{-}p \rightarrow K^{-}\Sigma^{+}$, and $\pi^{-}p \rightarrow K^{0}\Sigma^{0}$. It turned out however, that it is not possible to obtain a quantitative description of experimental data if only t- and u-channel (meson and baryon) exchange is taken into account for the transition potentials and the final state interaction. This indicates that the indusion of resonance contributions (s-channel exchange) is necessary in order to achieve a better agreement with the experiments