Orbitally Excited Baryons in Large N_c QCD

Abstract

We present a model-independent analysis of the mass spectrum of nonstrange l=1 baryons in large N_c QCD. The 1/N_c expansion is used to select and order a basis of effective operators that spans the nine observables (seven masses and two mixing angles). Comparison to the data provides support for the validity of the 1/N_c expansion, but also reveals that only a few nontrivial operators are strongly preferred. We show that our results have a consistent interpretation in a constituent quark model with pseudoscalar meson exchange interactions.

4 pages LaTeX. Invited parallel session talk presented at the XVth Particles and Nuclei International Conference (PANIC99), June 10, 1999, Uppsala, Sweden