2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/204883We 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.7 pages, 5 tablesHigh Energy Physics - Phenomenologytext