Light baryon resonances from a coupled-channel study including $\mathbf{K\Sigma}$ photoproduction

TL;DR

This study extends a coupled-channel approach to include $K ext{Sigma}$ photoproduction, analyzing extensive data to extract nucleon resonance spectra and assess the channels' impact on resonance properties.

Contribution

It introduces an extended coupled-channel model incorporating $K ext{Sigma}$ photoproduction and provides a comprehensive analysis of resonance spectra with new polarization data.

Findings

Resonance pole positions and residues were extracted.

The impact of $K ext{Sigma}$ channels on resonance properties was quantified.

Polarization data significantly influence the resonance analysis.

Abstract

The J\"ulich-Bonn dynamical coupled-channel approach is extended to include $K\Sigma$ photoproduction off the proton. Differential cross section and (double) polarization data for $K^+\Sigma^0$ and $K^0\Sigma^+$ are analysed simultaneously with the pion- and photon-induced production of $\pi N$, $\eta N$, $K\Lambda$, and $K\Sigma$ final states, totaling more than 67,000 data points for center-of-mass energies $W<2.4$ GeV. Based on the fit results the spectrum of $N^*$ and $\Delta$ resonances is extracted in terms of pole positions and residues. We discuss the impact of the $\gamma p\to K\Sigma$ channels in detail and investigate the influence of recent polarization data for $\eta p$ photoproduction.