Investigation of low energy pion-nucleus interaction using electrofission data for heavy nuclei at the pion threshold
1 Laboratori Nazionali di Frascati, Istituto Nazionale di Física
Nucleare, P.O. Box 13, I-00044 Frascati (Roma), Italy
2 Universidade de Santo Amaro/UNISA, São Paulo, Brasil
Received: 10 March 1998 / Revised version: 12 March 1999 Communicated by C. Signorini
A theoretical approach to describe electro- and photofission processes at intermediate energies was worked out. Photopion reabsorption mechanisms by two and three nucleons ( and ) were incorporated in the calculations. The comparison with electrofission data for preactinides showed that a substantial 3NA component should be added in the pion absorption to fit the data near photopion threshold, in accordance with a recent theoretical estimate. It was also shown that the shape of the fission response curve is sensitive to detailed aspects of the pion mean free path.
25.20.Lj Photoproduction reactions - 25.85.Jg Photofission