Level Crossing of N* (1535)-hole and η Modes and Partial Restoration of Chiral Symmetry in η-mesic Nuclei

摘要

We investigate the properties of the η-nucleus interaction by postulating the N* (1535) dominance for ηN system.Since the mass gap of N* and N is very close to the η meson mass,there is the possibility of the level crossing between the N*-h and η modes in finite density.We postulate the N* (1535) resonance for the ηN system and consider quite distinct N* properties in finite density which are predicted by two independent chiral models.We find that we can obtain clearer information on the in-medium N* properties and also on the η-nucleus interaction through the formation of the η-mesic nuclei by (π,N) reactions under the appropriate experimental conditions,which can be performed at existing and/or forthcoming facilities like J-PARC.