A systematic analysis of the spherical-to-deformed shape phase transition in even-even rare-earth nuclei from ${}^{58}\mathrm{Ce}$ to ${}^{74}\mathrm{W}$ is carried out in the framework of the interacting boson model. These results are then used to calculate nuclear radii and electric monopole ($E0$) transitions with the same effective operator. The influence of the hexadecapole degree of freedom ($g$ boson) on the correlation between radii and $E0$ transitions thus established is discussed.

• Received 16 January 2008

DOI:https://doi.org/10.1103/PhysRevLett.101.022502