Low lying K = 0⁺ bands in Gadolinium nuclei

In this paper we investigate the nature of the low-lying excited 0⁺ states in ^156,158,160Gd nuclei, in the framework of the pseudo-SU(3) model. We study the energy levels, their wave function contents, and the corresponding B(E2) transitions related to the excited 0⁺ states. The theory uses a realistic Hamiltonian with single-particle energies and monopole pairing interactions in addition to the usual quadrupole-quadrupole term, with the pairing and quadrupole-quadrupole strengths taken from systematics. The calculations are carried out with a set of basis states with pseudo-spin zero proton and neutron configurations. The calculated B(E2) values suggest that the first excited 0⁺ state might have a mixed nature of collective vibration, possible with quasiparticle excitations that are not considered in this calculation. (author)