Some Remarks on Exotic Resonances

Abstract

Using large $N_c$ counting rule, it is argued that tetra-quark resonances do not exist. Also it is pointed out that there exists the violation of exchange degeneracy in the exotic $KN$ scattering channel. It implies either the failure of resonance saturation assumption or it suggests the existence of exotic baryon resonances in such a channel.

Comments: Talk given at 10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2004), Beijing, China, 29 Aug - 4 Sep 2004