In-medium properties of N*(1535) in chiral models and η-nucleus interaction

We investigate the properties of η-nucleus interaction by postulating the N*(1535) dominance for η−N system. We evaluate the N*(1535) properties in the nuclear medium using two kinds of chiral models, and find that these two models provide qualitatively different η-nucleus optical potential reflecting the quite distinct properties of N*(1535) in these chiral models. We find also that the difference of these models can be seen in the formation cross sections of the η mesic nuclei with (d,3He) and (γ,p) reactions, which are expected to be distinguishable in experiments.