Nuclear structure in the framework of microscopic and phenomenological models

Abstract

This work involves the study of shape and structural changes of heavy neutron-rich nuclei in the framework of different microscopic and macroscopic nuclear models. The mean field Skyrme Hartree-Fock (SHF) plus Bardeen-Cooper-Schrieffer (BCS) treatment of pairing correlations and the beyond mean field Random Phase Approximation (RPA) represent the microscopic approach while the Algebraic Collective Model (ACM) serves as an example of a macroscopic approach. The work focuses on the systematics of binding energies in the chains of Te, Xe, Ba, Ce, and Nd isotopes beyond N = 82 with the aim of finding the Skyrme parametrization best fitting the experimental nuclear binding energies of the studied isotopes. We then investigate the evolution of quadrupole, octupole and hexadecapole deformation along the Te, Xe, Ba, and Ce isotopic chains within the SHF+BCS approach. The beyond mean field Skyrme-QRPA (quasiparticle RPA) enables in addition to study collective quadrupole and octupole vibrational states and even the position of the lowest 2+ rotational states in the isotopic chains. Another topic represents the investigation of single-neutron and single-proton states around the Fermi level along the Ce and Nd isotopic chains beyond N = 82 again within the SHF+BCS. From the macroscopic point of view, within the ACM, we investigate the basic properties of even-even xenon isotopes 128Xe and 130Xe, considered to be candidates for an E(5) transition from spherical to O(6)-like nuclei, and compared our results to those obtained using the SHF+BCS method.