E2 Decay Characteristics Of The M1 Scissors Mode Of Sm-152

The E2/M1 multipole mixing ratio of the 1(sc)(+) -> 2(1)(+) gamma-ray transition and therefore the F-vector E2 decay of the scissors mode of the shape-phase transitional nucleus Sm-152 have been measured with the nuclear resonance fluorescence method at the High-Intensity gamma-ray Source (HI gamma S). Furthermore, parity quantum numbers of several dipole-excited states have been remeasured, making use of the polarized gamma-ray beam at HI gamma S, and partially reassigned. The new data enable an unambiguous determination of the proton and neutron effective boson quadrupole charges within the proton-neutron interacting boson model. With the well-constrained parameter set, a new mixed-symmetry state is predicted.