Structure of the Anomalous 0+' Excited States in Spherical Even-Even Nuclei with N or Z 40

Abstract

A possible explanation of the characteristic systematic behaviour of the first excited 0+′ states in even-even nuclei with N or Z ≈40 is given by taking account of an important effect of the mutual interplay between the pairing and quadrupole correlations. After making it clear what physical situation in shell structure is essential for the appearance of the anomalous low-lying excited 0+′ states, we predict another possible mass-number region where the anomalous 0+′ states may be also realized.