Coupled-channel dynamics in the reactions piN --> piN, etaN, KLambda, KSigma

TL;DR

This paper develops a comprehensive coupled-channel model for meson-baryon interactions involving piN, etaN, and KLambda/Sigma channels, fitting experimental data and extracting resonance properties.

Contribution

It introduces an analytic, unitary coupled-channel approach that incorporates SU(3) symmetry to relate various meson-baryon interactions and determines resonance parameters from data.

Findings

Successfully describes multiple scattering and reaction data

Extracts resonance positions and branching ratios

Provides final-state interaction models for photoproduction analysis

Abstract

Elastic piN scattering and the world data of the family of reactions pi^- p --> eta n, K^0 Lambda$, K^0 Sigma^0, K^+ Sigma^-, and pi^+ p --> K^+ Sigma^+ are described simultaneously in an analytic, unitary, coupled-channel approach. SU(3) flavor symmetry is used to relate both the t- and the u- channel exchanges that drive the meson-baryon interaction in the different channels. Angular distributions, polarizations, and spin-rotation parameters are compared with available experimental data. Partial-wave amplitudes are determined and the resonance content is extracted from the analytic continuation, including resonance positions and branching ratios, and possible sources of uncertainties are discussed. The results provide the final-state interactions for the ongoing analysis of photo- and electroproduction data.