Spectroscopic properties of odd-mass rare-earth nuclei within a mean-field approach with time-reversal symmetry breaking

Abstract

The study of nuclear structure within mean-field approach has been in spotlight in recent years. For odd-mass nuclei, the one unpaired nucleon causes time-reversal symmetry breaking at the mean-field level. One way to address this issue is by adopting the Hartree-Fock-plus-Bardeen-Cooper-Schrieffer (HF+BCS) approach with self-consistent blocking (SCB). In the present work, some spectroscopic properties of odd-mass nuclei in the rare-earth region with atomic mass number, A in the range of 157 < A < 181 have been investigated within the HF+BCS framework with SCB using SIII Skyrme parameterization. The calculations were limited to nuclear shapes with axial and parity symmetries. In the BCS framework, seniority force was used to approximate the pairing interaction. The pairing strengths were determined by fitting the neutron and proton pairing strengths to reproduce experimental odd-even mass staggering and moment of inertia. The neutron and proton pairing strengths were found to be rather similar in both fitting procedures, with energy of 16 MeV and 15 MeV for neutron and proton, respectively. Calculations of odd-mass nuclei were performed starting from neighboring even-even nuclei. Spectroscopic properties that have been investigated are the spin and parity, charge radii, r , electric quadrupole moment, Q20, spectroscopic quadrupole moment, Q2(s)'), magnetic dipole moment, u, moment of inertia, I and band-head energy spectra. Overall, a qualitative agreement was obtained between the calculated and experimental data of all the properties mentioned. It can be concluded that this approach is able to describe the ground-state nuclear properties and rotational band-head of the chosen rare-earth nuclei.