Dipole excitations in the transitional nucleus [Formula Presented]Nd studied in photon scattering experiments

Low-lying electric and magnetic dipole excitations in the transitional nucleus [Formula Presented]Nd have been studied in nuclear resonance fluorescence experiments performed with a bremsstrahlung beam (end point energy 4.1 MeV). The use of high-resolution [Formula Presented]-ray spectrometers and a sectored single-crystal Compton polarimeter provided detailed information on excitation energies, spins, parities, decay widths, transition probabilities, and branching ratios of numerous new spin-1 states in [Formula Presented]Nd. The strong [Formula Presented]1 excitation at 2185 keV in this [Formula Presented] = 84 nucleus is interpreted as the quadrupole-octupole coupled two-phonon excitation which has been observed systematically in the neighboring [Formula Presented] = 82 isotones. The decay properties of this 1[Formula Presented] state are compared with the systematics of the low-lying 1[Formula Presented] levels in the other even-even, stable Nd isotopes. The [Formula Presented]1 excitations in [Formula Presented]Nd are discussed with respect to the deformation dependence of the orbital [Formula Presented]1 “scissors mode”, the so-called “[Formula Presented] law”, which has been studied previously in the other stable even-even Nd nuclei and in the Sm isotopes.