Fragmentation of single-particle and collective motions in the quasiparticle-phonon nuclear model

Abstract

Basic assumptions of the quasiparticle-phonon nuclear model are expounded. The model Hamiltonian is constructed. The system of equations is found and approximate equations are obtained. An exact inclusion of the Pauli principle in two-phonon components of the wave functions is studied. Our results are compared with those obtained within the nuclear field theory. A new method for improving the description of fragmentation of one-phonon states is expounded. Fragmentation of one-quasiparticle and one-phonon states is described and nuclear characteristics produced by fragmentation of these states are calculated. Examples are given of the calculated widths of E1-, E2-, E3- as well as M1- and M2- giant resonances. Fragmentation of charge-exchange Gamow-Teller and spin-dipole resonances in spherical and deformed nuclei are studied. The neutron and partial radiative strength functions are described. The fragmentation of deep-hole and high-lying states in spherical nuclei and their γ-decay are considered. The fragmentation of one-quasiparticle states in deformed nuclei is studied. The low-lying nonrotational K π = 0 +, 2 +, 3 + and 4 + states in deformed nuclei are described. The results of calculations of these states within the quasiparticle-phonon nuclear model and the interacting boson model are compared. The results of calculations are also compared with experimental data.