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

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.