Chirally motivated separable potential model for $\eta N$ amplitudes

TL;DR

This paper presents a chiral symmetry-based separable potential model for eta-nucleon interactions, predicting scattering lengths and subthreshold attraction that could lead to eta-nuclear bound states, and discusses resonance origins.

Contribution

It introduces a novel coupled channel separable potential model incorporating chiral symmetry for eta-nucleon interactions.

Findings

Predicts eta-N scattering length of about 0.7 fm

Suggests sufficient in-medium attraction for eta-nuclear bound states

Discusses common origin of N*(1535) and N*(1650) resonances

Abstract

We analyze the $\eta N$ interaction using a coupled channel separable potential model that implements the chiral symmetry. The model predicts an $\eta N$ stattering length $\Re a_{\eta N} \approx 0.7$ fm and in-medium subthreshold attraction most likely sufficient to generate $\eta$-nuclear bound states. The energy dependence of the $\eta N$ amplitude and pole content of the model are discussed. An idea of the same origin of the baryon resonances $N^{\star}(1535)$ and $N^{\star}(1650)$ is presented.