Analysis of Negative Parity Baryon Photoproduction Amplitudes in the $1/N_c$ Expansion

Abstract

We study the photoproduction helicity amplitudes of negative parity baryons in the context of the $1/N_c$ expansion of QCD. A complete analysis to next-to-leading order is carried out. The results show sub-leading effects to be within the magnitude expected from the $1/N_c$ power counting. They also show significant deviations from the quark model, in particular the need for 2-body effects.

Comments: 7 pages, 5 tables