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Knowledge of the exact microscopic structure of the 0(1)(+) ground state and first excited 0(2)(+) state in Sm-150 is required to understand the branching of double beta decay to these states from Nd-150. The detailed spectroscopy of Sm-150 and Gd-152 has been studied using (alpha, xn) reactions and the gamma-ray arrays AFRODITE and JUROGAM II. Consistently strong E1 transitions are observed between the excited K-pi = 0(2)(+) bands and the lowest negative parity bands in both nuclei. These results are discussed in terms of the possible permanent octupole deformation in the first excited K-pi = 0(2)(+) band and also in terms of the "tidal wave" model of Frauendorf. DOI: 10.1103/PhysRevC.87.044333

Excite states n even N isotopes, up to excitation energies of 3-4 MeV, were investigate in proton- and deuteron-scattering experiments performed with high-energy resolution. More than 300 transitions were studied. For several new excited states spin and parity assignments have been suggested. Reduced transition probabilities were extracted for natural-parity states from 0+ up to 6+. The experimental strength distributions have been compared with the predictions of the interacting boson model (IBM) and of the quasi-particle-phonon model (QPM). The octupole transition probabilities are well described in both models as produced by the fragmentation of the f-boson or of E3 phonons. IBM-sdf calculations seem to account also for the transitions to the low-lying 1- states. Quadrupole and hexadecapole distributions are well described in the QPM. The leading configurations are due to 6-8 low-lying one-phonon states. The two- and three-phonon states play an important role especially in Nd-146. The failure of IBM quadrupole and hexadecapole calculations clearly points out the need of introducing additional bosons lying at high excitation energies. QPM evaluations account also for other features of the experimental data, as the E5 and E6 strength distributions and the isovector components. The limits of the two models are discussed.

Excite states n even N isotopes, up to excitation energies of 3-4 MeV, were investigate in proton- and deuteron-scattering experiments performed with high-energy resolution. More than 300 transitions were studied. For several new excited states spin and parity assignments have been suggested. Reduced transition probabilities were extracted for natural-parity states from 0+ up to 6+. The experimental strength distributions have been compared with the predictions of the interacting boson model (IBM) and of the quasi-particle-phonon model (QPM). The octupole transition probabilities are well described in both models as produced by the fragmentation of the f-boson or of E3 phonons. IBM-sdf calculations seem to account also for the transitions to the low-lying 1- states. Quadrupole and hexadecapole distributions are well described in the QPM. The leading configurations are due to 6-8 low-lying one-phonon states. The two- and three-phonon states play an important role especially in Nd-146. The failure of IBM quadrupole and hexadecapole calculations clearly points out the need of introducing additional bosons lying at high excitation energies. QPM evaluations account also for other features of the experimental data, as the E5 and E6 strength distributions and the isovector components. The limits of the two models are discussed.