Meeting on Beauty in Physics - Theory and Experiment in Honor of Francesco Lachello on the Occasion of his 70th Birthday, Meksika, 14 - 18 Mayıs 2012, cilt.1488, ss.150-154
We show that delta V-pn values in the rare earth region show peaks, reminiscent of the spikes at N = Z in light nuclei, but occurring at N-val similar to Z(val). These peaks, evident for both even and odd Z values, are interpreted in terms of large spatial overlaps of respective proton and neutron wave functions whose Nilsson quantum numbers are related by delta K[delta N, delta n(z), delta A] = 0[110]. That is, the wave functions differ only by a single oscillator quantum in the z-direction. The implications of this for the development of collectivity and deformation in heavy nuclei, and the locus of this development, are discussed.