We present a detailed analysis of spectra and other observables for the entire chain of Zr isotopes, from neutron number 52 to 70, in the framework of the interacting boson model with configuration mixing. The results suggest a remarkable interplay of multiple quantum phase transitions (QPTs).One type of QPT involves an abrupt crossing of normal and intruder configurations, superimposed on a second type of QPT involving gradual shape-changes within each configuration.

No abstract

No 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.