Transition from {gamma}-rigid to {gamma}-soft dynamics in the interacting boson model: Quasicriticality and quasidynamical symmetry

We study the transition from the {gamma}-rigid to {gamma}-soft collective nuclear dynamics across the Casten triangle of the interacting boson model using mean-field techniques and confront the description with the exact diagonalization. We inspect the domain of validity of the SU(3) quasidynamical symmetry inside the Casten triangle and reveal critical behavior within the low-lying excited spectrum due to a degeneracy of {beta} and {gamma} vibrations.