The light baryon spectrum and the exchange of pseudoscalar and vector   mesons among constituent quarks
  The effects of the exchanges of both pseudoscalar and vector mesons among constituent quarks on the mass spectra of light baryons are investigated, paying particular attention to the contribution of tensor and spin-orbit terms. It is shown that the latter ones heavily affect the calculated spectra at variance with the empirical observation of the weakness of the baryon spin-orbit splittings. The relativistic suppression of the strength of the interaction among light quarks is argued to be a possible way to reproduce the light-baryon mass spectra. 
F. Cardarelli and S. Simula