Empirical estimates of the proton-neutron interaction and diabolical points

Abstract

The use of constant-N contours in the (w,A) plane is demonstrated both for establishing diabolical points and for studying regularities and fluctuations in the spectrum of single-particle states. Likewise the average properties and fluctuations of empirical proton-neutron interactions, obtained I from double differentials of the total energy with respect to N and Z, are discussed for the ground ! states of ail even-even nuclei with N>40 and as a function of the rotational frequency for the lowest even-spin, positive-parity decay sequence of deformed rare earth nuclei. i