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 R-4/2 of the first 4(+) to 2(+) states. The mean value of the cross-correlation coefficients, plotted as a function of R-4/2 has deep minima at values of R-4/2 = 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 R-4/2 classes has different pattern. (c) 2005 Elsevier B.V. All rights reserved.