Mutual Support of Magicities

Abstract

A strong correlation of neutron- and proton shell strengths is demonstrated by a systematic comparison of nuclear binding energies. Both, neutron- and proton shells show a maximum strength at doubly magic nuclei and generally fall down drastically with increasing number of additional particles or holes. This mutual support of shell strengths is not reproduced by usually applied theoretical shell corrections. Therefore, the results of shell model calculations, especially in the vicinity of doubly magic nuclei, concerning ground state shell corrections, fission barriers and decay energies, are expected to show appreciable shortcomings. If the variation of shell strengths is taken into account, the interpretation of the separation energies in terms of single particle energies is modified.. This modification could solve the ‘lead anomaly’, the difficulty in describing the ground state shell corrections and the separation energies around ²⁰⁸Pb simultaneously.