A new mixed formalism based on SU(1,1) transition Hamiltonian in the investigation of deformed states and transition rates of 124Te

Abstract

The existence of deformed states in nuclei such as 124Te leads to a change of the theoretical attitude to optimize the description of energy levels and electric quadrupole transition by using additional symmetries. The purpose of this contribution is to provide a detailed description of the energy gaps that appear in this nucleus using different mixing formalisms. To achieve this and also compare the accuracy of different formalisms, the transitional Hamiltonian in the affine SU(1,1) algebra was extended by adding the O(6)-Casimir operator. Also, the interacting boson model-2 is used to get theoretical predictions for the energy spectra and quadrupole transition rates of both regular and deformed states. Predictions of U(5) symmetry for the considered energy levels in 124Te nucleus show good agreement with experimental counterparts, except at 31+, 61+, and 62+ states where we tried to describe these levels by moving towards O(6) algebra. In this condition and using of both symmetries in the framework of mixing formalism, theoretical predictions for these deformed levels improved obviously, and transition probabilities were described in detail with high accuracy, too. Also, the IBM-2 suggests exact results for all regular states and intruder ones, and there are some suggestions about the advantages of each formalism in the description of energy levels and quadrupole transition rates of such nuclei.