Collective-model description of shape coexistence and intruder states in cadmium isotopes based on a relativistic energy density functional
K. Nomura, Konstantinos Karakatsanis
Abstract
Low-energy structure of even-even $^{108\ensuremath{-}116}\mathrm{Cd}$ isotopes is analyzed using a collective model that is based on the nuclear density functional theory. Spectroscopic properties are computed by solving the triaxial quadrupole collective Hamiltonian, with parameters determined by the constrained self-consistent mean-field calculations within the relativistic Hartree-Bogoliubov method employing a universal energy density functional and a pairing force. The collective Hamiltonian reproduces the observed quadrupole phonon states of vibrational character, which are based on the moderately deformed equilibrium minimum in the mean-field potential energy surface. In addition, the calculation yields a low-lying excited ${0}^{+}$ band and a $\ensuremath{\gamma}$-vibrational band that are associated with a deformed local minimum close in energy to the ground state, consistently with the empirical interpretation of these bands as intruder bands. Observed energy spectra, $B(E2)$, and ${\ensuremath{\rho}}^{2}(E0)$ values are, in general, reproduced reasonably well.