COMPARISONS OF THE ODD–EVEN STAGGERING PATTERNS BETWEEN THE Ba–Dy REGION WITH 88 NEUTRONS AND Ra ISOTOPES WITH 88 PROTONS

Abstract

Useful information about the shape transitions of even–even isotones 144 Ba , 146 Ce , 148 Nd , 150 Sm , 152 Gd , 154 Dy with 88 neutrons and 218-226 Ra isotopes with 88 protons are obtained from the ratios of [Formula: see text] as a function of neutron number N or proton number Z and the relations [Formula: see text] and r((I+2)/I) as a function of the angular momentum I. Interacting Boson Model (IBM-1), Bohr–Mottelson Model (BM) and Interacting Vector Boson Model (IVBM) have been employed to study the energy levels for the ground and octupole bands of the above nuclei. The best input parameters for the above approaches which lead to the best fit to experimental data are determined. The ΔI = 1 staggering (odd–even staggering) in octupole bands of the studied nuclei is found to exhibit a "beat" behavior as a function of angular momentum I. Comparisons of the displacement energies δE(I) and the staggering factor ΔE1, γ(I) are presented between the Ba–Dy region with 88 neutrons and Ra isotopes with 88 protons.