ar X iv : h ep - p h / 97 06 36 1 v 1 1 4 Ju n 19 97 1 Baryons , their interactions and the chiral symmetry of QCD

An implication of the spontaneous chiral symmetry breaking in QCD is that at low energy and resolution there appear quasiparticles-constituent quarks and Goldstone bosons. Thus, light and strange baryons should be considered as systems of three constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons between the constituent quarks. We show how the flavor-spin structure and sign of the short-range part of the Goldstone boson exchange interaction reduces the SU(6) F S symmetry down to SU(3) F × SU(2) S , induces hyperfine splittings and provides correct ordering of the lowest states with positive and negative parity. We present a unified description of light and strange baryon spectra calculated in a semirelativistic framework. It is demonstrated that the same short-range part of Goldstone boson exchange also induces strong short-range repulsion in NN system when the latter is treated as 6Q system. Thus all main ingredients of NN interaction are implied by the chiral constituent quark model since the long-and intermediate-range attraction appears in the present framework due to pion and correlated two-pion exchanges between quarks belonging to different nucleons. We also find a very strong short-range repulsion in ΛΛ system with J P = 0 +. It then suggests that the compact H-particle should not exist.