New data on nuclear subshells obtained from the analysis of the information from the international database on nuclear structure ENSDF

Abstract

In the last decade, a large amount of experimental nuclear spectroscopy data was obtained. This is good progress really, but a new very serious problem appears. Due to significant systematic errors of the data, one is often forced to deal with very discrepant data and often it is difficult to obtain reliable information from them. To solve this problem and to remove the systematic errors, new technologies in working with the data were developed. Using these new technologies, one can obtain information with a high accuracy and reliability, and in many cases, new information has not been or could not be obtained experimentally. Below, an approach of this kind is presented concerning spectroscopic data on Ca and Zr isotopes. It is shown that the behavior of the energy of the first 2+ level in Zr isotopes can be explained in the framework of a shell-model approach. A separation of the 2d 5/2 subshell in 96Zr (as is for the 1f 7/2 subshell in 48Ca) is found, so that the neutron number N=56 becomes like a magic number for Z=40. To explain a similarity in decaying properties of 48Ca and 96Zr, an additional interaction between closed structures consisting of 20 and 28 nucleons is proposed. Irregularities of the ground-state spin values in the K isotopic chain are explained in the framework of the shell-model approach by the inversion of the proton 1d 3/2 and 2s 1/2 orbitals.