Quark model: recent issues

Abstract

In the first part I briefly survey recent issues in constituent quark models raised by the observation of unusual hadronic states. In particular I discuss the role of higher Fock components in the wave function of baryons and the possible interpretation of open charm and of new charmonium-type resonances as tetraquarks. In the second part I show support for the quark model dynamics obtained in a model independent way from the $1/N_c$ expansion approach of QCD which proved to be successful in describing baryon properties.

Comments: 10 pages, invited talk at MENU2007, September 10-14, 2007, Juelich, Germany