Baryons in a chiral constituent quark model

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Abstract
In the low-energy regime light and strange baryons should be considered as systems of constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons as well as by vector and scalar mesons. The flavor-spin structure and sign of the short-range part of the spin-spin force reduce the St/(6)FS symmetry down to SU(3)F × SU(2)S, induce hyperfine splittings and provide correct ordering of the lowest states with positive and negative parity. There is a cancellation of the tensor force from pseudoscalar- and vector-exchanges in baryons. The spin-orbit interactions from p-like and ω-like exchanges also cancel each other in baryons while they produce a big spin-orbit force in NN system. A unified description of light and strange baryon spectra calculated in a semirelativistic framework is presented. It is demonstrated that the same short-range part of spin-spin interaction between the constituent quarks induces a strong short-range repulsion in NN system when the latter is treated as 6Q system. Thus one can achieve a simultaneous understanding of a baryon structure and baryon -baryon interaction in the low-energy regime.