Baryons, IN_c

Abstract

Excited baryons may be analyzed in the 1/N_c expansion as true resonances in scattering amplitudes. The key idea making this program possible is a generalization of methods originally applied to chiral soliton models in the 1980's. One finds model-independent relations among amplitudes that impose mass and width degeneracies among resonances of various quantum numbers. Phenomenological evidence demonstrates that patterns of resonant decay predicted by 1/N_c agree with data. The analysis can be extended to subleading orders in 1/N_c, where again agreement with data is evident.

Comments: 10 pages. Invited talk at "Continuous Advances in QCD 2004," Minneapolis, 13-16 May