Shape phase transition, coexistence, and mixing in the isotopes
Phys. Rev. C 114, 014335 – Published 28 July, 2026
DOI: https://doi.org/10.1103/tr8y-kcyq
Abstract
The deformation properties within the even-even isotopic chain, are investigated by means of the covariant density functional theory with a density-dependent point-coupling x parametrization. The considered nuclei are found to exhibit very shallow prolate and triaxial ground-state deformation. This information is used to ascertain their dynamical behavior within prolate -stable and -unstable instances of a phenomenological Bohr-Mottelson Hamiltonian with an octic potential in the axial deformation variable. The comparative study of the low-lying collective states, revealed the presence of a shape phase transition from low to high deformation, as well as evidence of shape coexistence and mixing between spherical vibrator, -unstable or prolate configurations in ground and excited states. It is also shown that the effect of shape coexistence and mixing on the -band states can account to some extent for the typical -unstable staggering even in prolate -stable conditions.