Description of Neutron and Radiative Strength Functions in the Quasiparticle-Phonon Nuclear Model

Abstract

The basic assumptions of the quasiparticle-phonon nuclear model (QPNM) are expounded as well as its advantages in describing nuclear states at low, intermediate and high excitation energies. It is shown that the spectroscopic factors of reactions of the type (d,p) and the neutron strength functions are determined by the fragmentation of one- and two-quasiparticle states. The QPNM calculations of neutron s-, p- and d-wave strength functions in spherical and deformed nuclei are presented. A correct description of the relevant data is obtained. The energy dependence of s- and d-wave strength functions for the tin isotopes is explained. The results of calculations of the spin splitting of s-wave strength functions are given. It was found to be small, that is in agreement with experimental data. The specific features of the calculations of radiative strength functions for Eλ and Mλ transitions from neutron resonances to low-lying states of spherical and deformed nuclei are discussed.