Structural evolution of 156→172Yb isotopic chain in the framework of extended CQF and catastrophe theory

In this paper, the authors applied the extended consistent Q formalism (E-CQF) of the sd-IBM and catastrophe theory to the Yb isotopic chain, namely, [Formula: see text], the critical and antispinodal points were obtained. The parameters of the Hamiltonian were determined using the method of orthogonal crossing contours (OCC), after that the Potential Energy Surfaces (PESs) for each isotope were obtained using the intrinsic coherent state formalism which manifests the classical limit of the theory, indicating a spherical to quadrupole deformed behavior. A comparison between the theoretical values of the yrast ground state and gamma band, as obtained from the Interacting Boson Model (IBM), and the experimental values was shown to have satisfactory agreement. Using the IBM parameters, a detailed illustration for the position of each isotope in the Casten symmetry triangle was also indicated, showing that the path of structural evolution for [Formula: see text] isotopic chain is not simply along the [Formula: see text]–[Formula: see text] side, but a more complicated path within the triangle itself.