On the 0⁺ excited states in even-even deformed nuclei

The low-lying 0⁺ excited states remain an object of particular interest in the nuclear structure physics. Recently long sets of 0⁺ excited states were experimentally observed. Our analysis of the experimental data have shown that in even-even nuclei of the rare-earth and actinide regions the energies of all low lying 0⁺ excited states with great accuracy can be distributed on parabolic functions of the number of monopole excitations building these states. Along with the classification of the energies of the 0⁺ excited states in respect to the number of bosons that build the band heads we analyze the role of their collectivity in the structure and evolution of the yrast bands and the B(E2) transition probabilities within these bands. The experimental determination in ¹⁶⁰Dy of the predicted in this way 0⁺ excited state with energy 0.6813 MeV is presented.