Recent soft-core baryon–baryon interactions

Abstract

Recent results obtained with the extended-soft-core (ESC) interactions are presented. In a unified manner the ESC-model describes nucleon–nucleon (NN), hyperon–nucleon (YN), and hyperon–hyperon (YY), using (broken) SUF(3)-symmetry. In the ESC approach to baryon–baryon (BB) the dynamics is derived from (i) one-boson-exchanges (OBE), (ii) two-meson-exchanges (TME), and (iii) meson-pair-exchanges (MPE). Special features are the inclusion of the axial-vector meson potentials, and a zero in the scalar-meson form-factors. With these ingredients a rather flexible dynamical framework is constructed. Namely, it appeared feasible to keep the parameters of the model rather close to the predictions of the P03 quark-pair-creation model (QPC). This is the case for the meson–baryon coupling constants and the F/(F+D)-ratios as well. The NN, YN, and YY results for this model are rather promising. Here, we report on a recently obtained version, called ESC04. Also, we present the first results with the next version, called ESC06, where we explore the inclusion of the second nonets for the pseudoscalar, vector, and scalar mesons, which have masses approximately in the interval 1GeV⩽M⩽1.5GeV. In the qq¯-picture these mesons are the radially excited states, with principal quantum number N=2, of the low lying meson nonets for M⩽1 GeV. This improves the Σ-well-depth considerably.