Nuclear shape phase transition in even-even 158−168Hf isotopes

Abstract

The interacting sdf-boson-approximation model is adopted to describe the low-lying positive and negative parity states in even-even 158−168Hf isotopes. The negative parity states are described using the sdf-IBM model by adding the L = 3 f-bosons nucleon pairs to the standard sd-boson model space. To determine the deformation of the nuclear structure of these isotopes the potential energy surfaces are calculated as functions of the deformation parameters. The reduced transition probabilities B(E2) in N = 94 are compared to the critical point symmetry X(5) predictions. In this chain, the sdf-boson interacting parameters are investigated and plotted against a number of neutrons. The shape phase transition from spherical 158Hf to well-deformed 168Hf nuclei is observed.