Cross correlation of low-lying levels of even–even nuclei

We consider the cross correlations of low-lying energy levels of nuclei belonging to small intervals of the excitation-energy ratio R4/2 of the first 4+ to 2+ states. The mean value of the cross-correlation coefficients, plotted as a function of R4/2 has deep minima at values of R4/2=2.2 and 2.9, which correspond to the critical dynamical symmetries of the interacting Boson model. The distribution of the calculated coefficients for nuclei belonging to different R4/2 classes has different pattern.