Quark-model baryon-baryon interactions and their applications to few-body systems

Abstract

The SU ₆ quark-model baryon-baryon interaction by the Kyoto-Niigata group is reviewed with an emphasis on the unknown hyperon-nucleon interactions, especially, the ΞN interaction. With a newly developed framework to derive the baryon-octet (B ₈) α interactions, we have examined Λα, Σα and Ξα central and LS potentials predicted by our models fss2 and FSS through the G-matrix calculations in symmetric nuclear matter. Our Λβ potential is comparable to the ones from the effective ΛN forces. The Λα LS potential by FSS is consistent with the very small spin-orbit splitting of ⁹ _Λ Be, experimentally observed. The Σα potential is repulsive due to the very strong repulsion in the isospin I = 3/2 ³ S ₁ ΣN channel, which is induced from the Pauli principle at the quark level. A similar strong isospin dependence of the ΞN interaction implies that Ξα central potential may not be strongly attractive, merely having an attraction of less than 5 MeV at the surface region. The Λ(3N), Σ(3N) and Ξ(3N) central potentials are also discussed.