Energy spectra and quadrupole transition probabilities

In this paper, we have studied the energy spectra and B(E2) transition probabilities of 124-130 Ba isotopes in the shape phase transition region between the spherical and gamma unstable deformed shapes. We have used a transitional Interacting Boson Model Hamiltonian which is based on affine SU(1,1) Lie Algebra in the both IBM-1 and 2 versions and also the Catastrophe theory in combination with a coherent state formalism to generate energy surfaces and determine the exact values of control parameters. Our results for control parameters suggest a combination of U(5) and SO(6) dynamical symmetries in this isotopic chain. Also, the theoretical predictions can be rather well reproduce the experimental counterparts when the control parameter is approached to the SO(6) limit. BE transition probabilities.