Structural evolution and shape transitions of even-even neutron rich ^140-150 Ba nuclei using triaxial projected shell model

The neutron rich barium isotopes with six valence protons represent the commencement of collective rotation-vibration band structure. In the present work, the application of triaxial projected shell model has been made with the aim of understanding the nuclear structure of neutron rich barium isotopes with mass number ranging from 140 to 150. The calculations have been done in a self consistent manner and degree of axial and non-axial deformation present in these nuclei has been estimated. Calculated results on the level structure of yrast and near-yrast bands provide good agreement with the experimental data. The present work demonstrates that these isotopes perform rapid shape phase transition between U(5) ⟶ SU(3) as one moves away from N = 82 major shell closure. In addition to this, various structural properties like back-bending in moment of inertia, staggering in γ -vibrational bands, E-GOS systematics, etc. have been analysed in order to probe the nuclear structure of chosen isotopes. Also, it is pointed out that the TPSM predictions are equitably reliable for the detailed description of inter-band and intra-band B(E2) transition probabilities for these isotopes.