The Nijmegen Hyperon-Nucleon and Hyperon-Hyperon Interactions

In this talk we review results of the Nijmegen soft-core NSC97 OBE-models^1,2,3. After a general introduction, we first describe the Nijmegen approach to the baryon-baryon problem, and picture the baryon-baryon interactions in the general framework of QCD, flavor SU(3), and chiral SU(3) ⊗ SU(3). Stressed is the simultaneous description of all baryon -baryon channels. Then, we discuss the interactions and the treatment of mesons, emphasizing the important role of the scalar-meson nonet. Next, we describe some of the results of the YN-channels (S = -1) with the new models NSC97a-f in some detail. Finally, since the nucleon-nucleon and hyperon-nucleon data fitting determined all free parameters in the NSC97 models, using (broken) SU(3)-symmetry, predictions for all other baryon-baryon channels can be given. We report briefly on the results for the S = -2, -3, -4 NΞ and YY systems. Here several bound states are predicted.