Features of p-induced collective resonances in nuclei A semi-empirical model for collective nuclear resonances in the ? energy region

A semi-empirical model is presented for the excitation of collective nuclear resonances induced by pions on nuclei in the ?(1232) energy region. The physical features of the collective states have been extracted according to the model by fitting data from a collection of resonant p-nucleus elastic scattering cross-sections. The contributions to the total binding energy and to the width of a collective state per each additional nucleon involved in the resonance have been extracted. The interaction between the collective resonances and the surrounding nuclear medium is discussed.