Quark-model Baryon-baryon Interaction and Its Applications to Hypernuclei * )

The quark-model baryon-baryon interaction fss2, proposed by the Kyoto-Niigata group, is a unified model for the complete baryon octet (B8 = N , Λ, Σ and Ξ), which is formulated in a framework of the (3q)-(3q) resonating-group method (RGM) using the spin-flavor SU6 quark-model wave functions and effective meson-exchange potentials at the quark level. Model parameters are determined to reproduce properties of the nucleon-nucleon system and the low-energy cross section data for the hyperon-nucleon scattering. Due to the several improvements including the introduction of vector-meson exchange potentials, fss2 has achieved very accurate description of the NN and Y N interactions, comparable to various one-boson exchange potentials. We review the essential features of fss2 and our previous model FSS, and their predictions to few-body systems in confrontation with the available experimental data. Some characteristic features of the B8B8 interactions with the higher strangeness, S = −2, − 3, − 4, predicted by fss2 are discussed. These quark-model interactions are now applied to realistic calculations of few-body systems in a new three-cluster Faddeev formalism which uses two-cluster RGM kernels. As for the few-body systems, we discuss the three-nucleon bound states, the ΛNN-ΣNN system for the hypertriton, the ααΛ system for ΛBe, and the ΛΛα system for 6 ΛΛHe.