The pseudoscalar meson and baryon octet interaction in the unitary coupled-channel approximation

TL;DR

This paper investigates pseudoscalar meson-baryon interactions using a nonlinear Lagrangian and coupled-channel Bethe-Salpeter equations, successfully generating resonances corresponding to known particles like Lambda(1405) and N(1535).

Contribution

It introduces a detailed coupled-channel approach with nonlinear Lagrangian to dynamically generate baryon resonances.

Findings

Generated a pole near 1400MeV corresponding to Lambda(1405).

Produced a resonance around 1500MeV potentially related to N(1535).

Demonstrated the effectiveness of the unitary coupled-channel method.

Abstract

The pseudoscalar meson-baryon octet interaction is studied within a nonlinear realized Lagrangian, and then the Bethe-Salpeter equation is solved in the unitary coupled-channel approximation. In sector of strangeness $S=-1$ and isospin $I=0$, only one pole is generated dynamically in the 1400MeV region, which might correspond to the $\Lambda(1405)$ particle. When the case of strangeness zero is studied, the $s-$ and $u-$ potentials are taken into account in the kernel, and a resonance state is produced in the 1500MeV region, which might be a counterpart of the N(1535) particle.