الملخص

Abstract In this work the Interacting Boson Model IBM-1, Davydov-Filippov (D-F) models and the Critical Point Symmetry X(5) have been employed to study the energy levels and the reduced transition probability B(E2) for the )N = 90( transitional nuclei 146Ba,148Ce,158Er and 160Yb in the concepts of theoretical treatment. The best input parameters for the above approaches which lead to the best fit to experimental data are determined. The reduced transition probability B(E2) for the above nuclei have been calculated in a relative and absolute scales by using the most recent available experimental data.