The qq spectrum is studied in a generalized constituent quark model constrained in the study of the N N phenomenology and the baryon spectrum. An overall good fit to the available experimental data is obtained. A detailed analysis of all sectors from the light-pseudoscalar and vector mesons to bottomonium is performed paying special attention to the existence and nature of some non well-established states. These results should serve as a complementary tool in distinguishing conventional quark model mesons from glueballs, hybrids or multiquark states.

Abstract. We review the application of non-relativistic constituent quark models to study one, two and three non-strange baryon systems. We present results for the baryon spectra, potentials and observables of the NN, N∆, ∆∆ and NN * (1440) systems, and also for the binding energies of three non-strange baryon systems. We make emphasis on observable effects related to quark antisymmetry and its interplay with quark dynamics.

We investigate the structure of heavy baryons containing a charm or a bottom quark. We employ a constituent quark model successful in the description of the baryon-baryon interaction which is consistent with the light baryon spectra. We solve exactly the three-quark problem by means of the Faddeev method in momentum space. Heavy baryon spectrum shows a manifest compromise between perturbative and nonperturbative contributions. The flavor dependence of the one-gluon exchange is analyzed. We assign quantum numbers to some already observed resonances and we predict the first radial and orbital excitations of all states with J = 1/2 or 3/2. We combine our results with heavy quark symmetry and lowest-order SU (3) symmetry breaking to predict the masses and quantum numbers of six still non-measured groundstate beauty baryons.

t lnstitut fiir Theoretische Phydk, University of Tobingen. D-7400 Tiibingen, Federal Republic of Germany Received I July 1993Abstrad. A modilied quarkquark interaction is applied to study lhe nucleon-nucleon interaction. The quark potential is suggested by inslanton models and includes pion (n) and sigma ( 0 ) exchanges as non-perturbative components and the one-gluon exchange as a pemrbative one. The nucleon-nucleon potential derived from this model presents short-range repulsion and mediun-range attraction besides the usual pion tail. Using this interaction the nucleon-nucleon phase shifts within the resonating group method have been olculated. They agree reasonably well with experimental values.

The recent observation at CDF and D0 of Σ b , Σ * b and Ξ b baryons opens the door to the advent of new states in the bottom baryon sector. The states measured provide sufficient constraints to fix the parameters of phenomenological models. One may therefore consistently predict the full bottom baryon spectra. For this purpose we have solved exactly the three-quark problem by means of the Faddeev method in momentum space. We consider our guidance may help experimentalists in the search for new bottom baryons and their findings will help in constraining further the phenomenological models. We identify particular states whose masses may allow to discriminate between the dynamics for the light-quark pairs predicted by different phenomenological models. Within the same framework we also present results for charmed, doubly charmed, and doubly bottom baryons. Our results provide a restricted possible assignment of quantum numbers to recently reported charmed baryon states. Some of them are perfectly described by D−wave excitations with J P = 5/2 + , as the Λ c (2880), Ξ c (3055), and Ξ c (3123).