Electromagnetic Excitation of Nucleon Resonances

TL;DR

This paper reviews recent progress in extracting electromagnetic properties of nucleon resonances using pion photo- and electroproduction data from major facilities, deriving transition form factors and charge densities.

Contribution

It provides a comprehensive analysis of experimental data to derive transition form factors and visualizes empirical transverse charge densities for key nucleon resonances.

Findings

Derived longitudinal and transverse transition form factors for most four-star nucleon resonances.

Produced contour plots of empirical transverse charge densities for Delta, Roper, S11, and D13 resonances.

Compared data analysis results across multiple experimental groups.

Abstract

Recent progress on the extraction of electromagnetic properties of nucleon resonance excitation through pion photo- and electroproduction is reviewed. Cross section data measured at MAMI, ELSA, and CEBAF are analyzed and compared to the analysis of other groups. On this basis, we derive longitudinal and transverse transition form factors for most of the four-star nucleon resonances. Furthermore, we discuss how the transition form factors can be used to obtain empirical transverse charge densities. Contour plots of the thus derived densities are shown for the Delta, Roper, S11, and D13 nucleon resonances.