Low-lying mixed symmetry states in the N=84 isotones ¹⁴⁰Ba and ¹⁴²Ce within interacting boson model-2

Abstract

The characteristics of the low-lying mixed-symmetry states for 140Ba and 142Ce in the even-even N=84 isotones are investigated within the framework of the IBM-2 model. Electromagnetic transitions, B(E2) and B(M1) were calculated. Results showed that the lowest mixed-symmetry state is for 140Ba and 142Ce nuclei. A good agreement is found between experiment and predictions made using the U (5) limit of IBM-2.