Shell model description of normal parity bands in even-even heavy deformed nuclei (original) (raw)

The pseudo-SU͑3͒ model is used to describe the low-energy spectra and electromagnetic transition strengths in 156 Gd, 158 Gd, and 160 Gd. The Hamiltonian includes spherical single-particle energies, the quadrupolequadrupole interaction, proton and neutron pairing interactions, plus four rotorlike terms. The quadrupolequadrupole and pairing interaction strengths are assigned the values ϭ23A Ϫ5/3 and G ϭ21/A, G ϭ17/A, respectively. The single-particle energies were taken from experiment but scaled to yield an overall best fit. For the other four rotorlike terms, which do not mix SU͑3͒ representations and induce only small changes in the spectra, a consistent set of parameters is given. The basis states are built as linear combinations of SU͑3͒ states which are the direct product of SU͑3͒ proton and neutron states with pseudospin zero. The results are in good agreement with experimental data, demonstrating the suitability of the model to describe heavy deformed nuclei.