Chiral Dynamics and the S₁₁(1535) Nucleon Resonance

الأصل · EN

The SU(3) chiral effective lagrangian at next-to-leading order is applied to the S-wave meson-baryon interaction in the energy range around the ηN threshold. Potentials are derived from this lagrangian and used in a coupled channel calculation of the πN, ηN, K Λ, K Σ system in the isospin-1/2, l=0 partial wave. Using the same parameters as obtained from a fit to the low energy K N data it is found that a quasi-bound K Σ-state is formed, with properties remarkably similar to the S₁₁(1535) nucleon resonance. In particular, we find a large partial decay width into ηN consistent with the empirical data.