Amplitude analysis of $\bar{K}N$ scattering

TL;DR

This paper develops a coupled-channel model for antikaon-nucleon scattering, accurately describing hyperon spectra and providing insights into the nature of the $ ext{Lambda}(1405)$ resonances.

Contribution

It presents a unitarity-preserving, analytically consistent coupled-channel model fitted to partial waves, offering a detailed hyperon spectrum analysis and insights into $ ext{Lambda}(1405)$.

Findings

Hyperon spectra $ ext{Lambda}^*$ and $ ext{Sigma}^*$ obtained.

Model fits partial waves up to 2.15 GeV and $J=7/2$.

Insights into the structure of $ ext{Lambda}(1405)$ resonances.

Abstract

We present the results of a coupled-channel model for $\bar{K}N$ scattering in the resonance region. The model fulfills unitarity, has the correct analytical properties for the amplitudes and the partial waves have the right threshold behavior. The parameters of the model have been established by fitting single-energy partial waves up to $J=7/2$ and up to 2.15 GeV of center-of-mass energy. The $\Lambda^*$ and $\Sigma^*$ spectra has been obtained, providing a comprehensive picture of the $S=-1$ hyperon spectrum. We use the structure of the hyperon spectrum and Regge phenomenology to gain insight on the nature of the $\Lambda(1405)$ resonances.