Quasi-particle and collective structure of the states of even, strongly-deformed nuclei

Abstract

The structure of the non-rotational excited states of even, deformed nuclei in the ranges 150≦ A ≦ 186 and 228 ≦ A ≦ 254 is investigated. The energies of the first and second K π = 2 + and 0 + states are calculated taking into account the blocking effect in the framework of the method of approximate second quantization. These energies agree sufficiently well with the corresponding experimental data. The structure of the excited states is investigated and it is found that in most cases the lowest lying K π = 2 +, 0 + states possess clearly expressed collective properties. In some cases the energies of quadrupole excited states lie near the secular equation poles and the structure of K π = 2 + states is similar to the two-quasi-particle ones. The particularities of the K π = 0 + states are investigated. The spectroscopic factors are calculated for direct nuclear reactions and the relative probabilities are found for beta transitions to the K π = 0 + states. A satisfactory agreement is obtained between theory and experiment. The role of the F and Q forbiddennesses in the superfluid nuclear model is investigated.