Coupled-channel contributions to the GDH sum rule from the J\"ulich-Bonn approach

TL;DR

This paper uses a coupled-channel approach to analyze the GDH sum rule, incorporating extensive pion and photon data to understand resonance contributions and channel impacts.

Contribution

It introduces a comprehensive coupled-channel analysis of the GDH sum rule using the Jülich-Bonn model with new and existing data.

Findings

New data significantly influence the resonance spectrum.

Individual channel contributions to the GDH integral are quantified.

The approach improves understanding of light baryon resonances.

Abstract

We study the Gerasimov-Drell-Hearn (GDH) sum rule within a dynamical coupled-channel approach, the J\"ulich-Bonn model for light baryon resonances based on fits to an extensive data base of pion and photon induced data. Recently published photoproduction data for different observables with $\pi N$ and $\eta N$ final states are analyzed simultaneously with older data for the reactions $\pi N\to \pi N$, $\eta N$, $K\Lambda$, $K\Sigma$ and $\gamma p\to\pi N$, $\eta N$, $K\Lambda$, $K\Sigma$. The impact of the new data on the resonance spectrum is investigated and the contribution of the individual channels to the GDH integral is determined.