Calculation of the Positive Parity Yrast Bands of 190–198Hg Nuclei

Abstract

The Interacting Boson Model (IBM-1) has been used to calculate the low-lying positive parity yrast bands in 190−198 Hg nuclei. The systematic yrast level and electric reduced transition probabilities B(2)↓ of those nuclei are calculated and compared with the available experimental data. The ratio of the excitation energies of first 4 + and first 2 + excited states, 4/2 , is also studied for the O(6) symmetry for these nuclei. Furthermore, as a measure to quantify the evolution, we have studied systematically the yrast level = + 1 / 2 + 1 of some of the lowlying quadrupole collective states in comparison to the available experimental data. Moreover, we have studied the systematic B(2) values, and the moment of inertia as a function of the squared rotational energy for even proton = 80 and 110 118 nuclei indicates the disappearance of back-bending properties. The results of this calculation are in good agreement with the corresponding available experimental data. The analytic IBM-1 calculation of the yrast level and B(2) values of even-even Hg nuclei is performed in the framework of O(6) symmetry. The contour plot of the potential energy surfaces shows that the nuclei are deformed and have-unstable-like characters.