Correlations of nuclear charge radii with other nuclear observables

Empirical correlations between nuclear charge radii and several other experimental ground and excited state observables of even-even nuclei are presented for different regions in the nuclear chart. The correlation among the isotonic development of these observables around the classical magic proton numbers is considered starting from Z = 82 to lower magic Z. Special attention is paid to the structural evolution along the isotonic chains around the 'traditional' magic proton numbers 8 and 20. The remarkable correlations recognized there indicate shell structure changes and the appearance of new non-traditional single or double magic-like numbers, as Z = 6, 14, 16. The results add new information to the properties of light nuclei. As the mechanisms responsible for the modification of nuclear shell closures are still under discussion, the experimental information obtained is of crucial importance to better constrain the theoretical models. The effect of nuclear deformation on radii and their global correlation over the full mass number region is also investigated.