STUDY OF IN-MEDIUM PROPERTIES OF N*(1535) AND CHIRAL SYMMETRY FOR BARYONS THROUGH THE η-MESIC NUCLEI FORMATION AT J-PARC

We investigate the properties of eta-nucleus interaction by postulating the N*(1535) dominance for eta-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 eta-nucleus optical potentials reflecting the quite distinct properties of N*(1535) in these chiral models. Especially, in the chiral doublet model, we can expect to have the level crossing between eta and N*(1535)-hole which is expected to provide the characteristic features for the optical potential and the formation spectra. We find also that the difference of these models can be seen in the formation cross sections of the eta mesic nuclei with (pi(+),p) reaction expected to be performed at J-PARC project.