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.

Comments: 32 pages, 8 figures, a slightly extended (two paragraphs added) version that matches the paper accepted for publication in Nuclear Physics A