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

TL;DR

This paper analyzes negative parity baryon photoproduction amplitudes using the $1/N_c$ expansion of QCD, revealing sub-leading effects and the importance of 2-body interactions, differing from traditional quark model predictions.

Contribution

It provides a comprehensive next-to-leading order analysis of baryon photoproduction amplitudes within the $1/N_c$ framework, highlighting the significance of 2-body effects.

Findings

Sub-leading effects are within expected $1/N_c$ magnitude.

Significant deviations from the quark model.

Necessity of including 2-body effects.

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.