The ${\bar K}N$ interaction in higher partial waves

TL;DR

This paper develops a chiral ${ar K}N$ interaction model incorporating higher partial waves, improving the description of meson-baryon scattering data at energies around 2 GeV.

Contribution

It introduces a detailed derivation of partial wave amplitudes from the chiral SU(3) Lagrangian up to d-waves and implements a nonperturbative unitarization to enhance data modeling.

Findings

Higher partial waves extend the energy range of accurate scattering data description.

The model accounts for structures in reaction cross sections beyond s-wave limitations.

Encouraging results suggest improved understanding of meson-baryon interactions at higher energies.

Abstract

We present a chiral ${\bar K}N$ interaction model that has been developed and optimized in order to account for the experimental data of inelastic ${\bar K}N$ reaction channels that open at higher energies. In particular, we study the effect of the higher partial waves which originate directly from the chiral Lagrangian, as they could supersede the role of high-spin resonances employed in earlier phenomenological models to describe meson-baryon cross sections in the 2~GeV region. We present a detailed derivation of the partial wave amplitudes that emerge from the chiral SU(3) meson-baryon Lagrangian up to the d-waves and next-to-leading order in the chiral expansion. We implement a nonperturbative unitarization in coupled channels and optimize the model parameters to a large pool of experimental data in the relevant energy range where these new contributions are expected to be important. The obtained results are encouraging. They indicate the ability of the chiral higher partial waves to extend the description of the scattering data to higher energies and to account for structures in the reaction cross sections that cannot be accommodated by theoretical models limited to the s-waves.