The reaction $\pi N \to \omega N$ in a dynamical coupled-channel approach

TL;DR

This paper extends a coupled-channel model to include the $oldsymbol{ extomega N}$ final state, analyzing light meson-baryon scatterings and extracting resonance spectra, with implications for $ extomega$ meson bound states in nuclear matter.

Contribution

It introduces the $ extomega N$ channel into the dynamical coupled-channel approach and provides a comprehensive analysis of resonance spectra from experimental data.

Findings

Extracted $N^*$ and $oldsymbol{ extDelta}$ resonance poles.

Found a negative $ extomega N$ elastic scattering length.

Questioned the existence of $ extomega$ meson bound states in nuclear matter.

Abstract

A refined investigation on light flavor meson-baryon scatterings is performed using a dynamical coupled-channel approach, the J\"ulich-Bonn model, that respects unitartiy and analyticity constraints. The channel space of $\pi N$, $\pi \Delta$, $\sigma N$, $\rho N$, $\eta N$, $K \Lambda$ and $K \Sigma$ is extended by adding the $\omega N$ final state. The spectra of $N^*$ and $\Delta$ resonances are extracted in terms of complex poles of the scattering amplitudes, based on the result of a global fit to a worldwide collection of data, in the energy region from the $\pi N$ threshold to center-of-mass energy $z=2.3$ GeV. A negative value of the $\omega N$ elastic spin-averaged scattering length is extracted, questioning the existence of bound states of the $\omega$ meson in the nuclear matter.