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arXiv · 0811.4516

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

H. Nagahiro·D. Jido·S. Hirenzaki
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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.

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H. Nagahiro, D. Jido, S. Hirenzaki. 2008-11-27. Formation of eta-mesic nuclei by (pi,N) reaction and N^*(1535) in medium. https://doi.org/10.1103/physrevc.80.025205

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