Formation of eta-mesic nuclei by (pi,N) reaction and N^*(1535) in medium

Abstract

We calculate formation spectra of eta-nucleus systems in (pi,N) reactions with nuclear targets, which can be performed at existing and/or forthcoming facilities, including J-PARC, in order to investigate eta-nucleus interactions. Based on the N^*(1535) dominance in the eta N system, eta-mesic nuclei are suitable systems for study of in-medium properties of the N^*(1535) baryon resonance, such as reduction of the mass difference of N and N^* in nuclear medium, which affects level structure of the eta and N^*-hole modes. We find that clear information on the in-medium N^*- and eta-nucleus interactions can be obtained through the formation spectra of the eta-mesic nuclei. We also discuss the experimental feasibilities by showing several spectra of (pi,N) reactions calculated with possible experimental settings. Coincident measurements of pi N pairs from the N^* decays in nuclei help us to reduce backgrounds.

12 pages, 10 figures

References in corpus (8)

• In-medium nuclear interactions of low-energy hadrons
• Origin of resonances in the chiral unitary approach
• In-medium Pion and Partial Restoration of Chiral Symmetry
• Level crossing of particle-hole and mesonic modes in eta mesic nuclei
• Photoproduction of eta-mesons off nuclei for Eg < 2.2 GeV
• Surface and volume effects in the photoabsorption of nuclei
• Eta-mesic nuclei in relativistic mean-field theory
• The structure of N(1535) in the aspect of chiral symmetry