Quadrupole phonons in the cadmium isotopes

Abstract

A key question concerning the spherical-vibrator attributes of states in Cadmium isotopes is addressed by means of a boson Hamiltonian encompassing U(5) partial dynamical symmetry. The U(5) symmetry is preserved in a segment of the spectrum and is broken in particular non-yrast states, and the resulting mixing with the intruder states is small. The vibrational character is thus maintained in the majority of low-lying normal states, as observed in 110 Cd.

Shape coexistence and multiparticle-multihole structures in Cd110,112

“…As given in Ref. [79], it is the 2 + 6 level that is predicted to have this character, with dominant E2 decays of B(E2; 2 + 6 → 0 + 4 ) = 24.3 W.u., B(E2; 2 + 6 → 4 + 1 ) = 15.7 W.u., B(E2; 2 + 6 → 2 + 2 ) = 9.3 W.u., and B(E2; 2 + 6 → 4 + 3 ) = 3.6 W.u. The data presented in Fig.…”

“…Thus, while the states are assigned as part of bands, the configurations may change as a function of spin, and in these cases, it is the presence of the large B(E2) value that permits the assignment into band sequences. The results presented in Table III Finally, for completeness in Table III, we present the results of recent interacting boson model calculations for 110 Cd by Leviatan et al [79] that incorporated configuration mixing within a partial-dynamical symmetry approach (PDS-CM). These calculations utilized a term in the Hamiltonian that preserved the U (5) symmetry for some parts of the spectrum, while it was broken for a subset of non-yrast states [79].…”

“…The results presented in Table III Finally, for completeness in Table III, we present the results of recent interacting boson model calculations for 110 Cd by Leviatan et al [79] that incorporated configuration mixing within a partial-dynamical symmetry approach (PDS-CM). These calculations utilized a term in the Hamiltonian that preserved the U (5) symmetry for some parts of the spectrum, while it was broken for a subset of non-yrast states [79]. Unlike the present BMF calculations, the PDS-CM is a fit to the excitation energy spectrum and the transition B(E2) values.…”

Partial Dynamical Symmetry and the Phonon Structure of Cadmium Isotopes

“…The combined effect of normal and intruder states, can be studied within the interacting boson model with configuration mixing (IBM-CM) [12]. The Hamiltonian for the two configurations has the form [4],…”

“…Recent studies, however, have cast doubt on the validity of this description [2,3]. In the present contribution, we address this question from a symmetry-oriented perspective, focusing on 110 Cd [4].…”