Photoproduction of pions and properties of baryon resonances from a Bonn-Gatchina partial wave analysis

TL;DR

This paper presents a comprehensive partial wave analysis of baryon resonances, determining their properties through a coupled-channel approach and extending the Bonn-Gatchina formalism to include detailed exchange amplitude decompositions.

Contribution

It introduces an extended Bonn-Gatchina formalism that incorporates t- and u-channel exchange amplitudes into partial wave analysis of baryon resonances.

Findings

Masses, widths, and photocouplings of baryon resonances determined.

Multipole transition amplitudes for specific photoproduction processes provided.

Comparison with other analyses shows consistency and improvements.

Abstract

Masses, widths and photocouplings of baryon resonances are determined in a coupled-channel partial wave analysis of a large variety of data. The Bonn-Gatchina partial wave formalism is extended to include a decomposition of t- and u-exchange amplitudes into individual partial waves. The multipole transition amplitudes for $\gamma p\to p\pi^0$ and $\gamma p\to n\pi^+$ are given and compared to results from other analyses.