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The current status of 2+ mixed-symmetry states in weakly deformed nuclei is described, and recent contributions from the (n,n’γ) reaction to our understanding of these states in nuclei around 94Mo are reviewed. The recent identification and characterization of two-phonon states, which are composed of the 2+ mixed-symmetry state coupled with the 2+ symmetric quadrupole phonon, are particularly significant and help clarify the picture of mixed-symmetry states as being generally occurring collective excitations. [ABSTRACT FROM AUTHOR]

Low-lying dipole excitations in the medium-weight vibrational nuclei of the Cd isotopic chain were investigated by means of nuclear resonance fluorescence experiments performed at the bremsstrahlung beam of the Stuttgart Dynamitron accelerator (endpoint energy 4.1 MeV). Detailed information has been obtained on excitation energies, spins, decay widths, and transition probabilities of numerous excited states in [sup 110-114,116]Cd. Additionally, the use of two Compton polarimeters enabled model-independent parity assignments for excitations in the even-even isotopes. Strongly excited J[sup π] = 1-states are found in all even-even Cd nuclei at excitation energies near the sum of the energies of the first 2[sup +] and 3[sup -] states. These excitations are interpreted as the 1[sup -] member of the quadrupole-octupole coupled quintuplet (2[sup +] ⊗ 3[sup -]). The fragmented strength observed in the odd isotopes [sup 111,113]Cd is compared with the strength distributions in the neighboring even-even Cd isotopes. [ABSTRACT FROM AUTHOR]

The low-spin structure of 93Nb has been studied using the (n,n’γ) reaction at neutron energies ranging from 1.5 to 2.6MeV and the 94Zr(p, 2nγ)93Nb reaction at bombarding energies from 11.5 to 19MeV. Excitation functions, lifetimes, and branching ratios were measured, and multipolarities and spin assignments were determined. The Jπ = 3/2- and 5/2- states at 1840 and 2013keV, respectively, are identified as mixed-symmetry states associated with the $\ensuremath{(2_{1,{\rm ms}}^{+}) \otimes 2_{p_{1/2}}}$ particle-core coupling. These assignments are in agreement with energy systematics, spins and parities, and the observed strong M1 transitions to the 2 p1/2 one-phonon structure. [ABSTRACT FROM AUTHOR]

The low-lying structure of 112Sn has been studied. γ-ray excitation functions, ranging from 2.5 to 4.0MeV, and angular distributions at 2.9 and 3.8MeV have been measured following the (n,n′γ) reaction to characterize the decays of the excited levels. Level lifetimes have been measured with the Doppler-shift attenuation method. Low-lying 1-, (2-), 3- and, 5- states have been identified as members of the heterogeneous quadrupole-octupole quintuplet. Decay properties and excitation energies are consistent with the structure formed by the coupling of the lowest quadrupole, 21+, and octupole, 31-, excitations. [ABSTRACT FROM AUTHOR]

Internal conversion coefficients have been measured for transitions in 110Pd to allow the determination of electric monopole (E0) transition strengths. Excited states were populated through inelastic alpha scattering and the SPICE+TIGRESS detectors at TRIUMF-ISAC-II were used to detect the emitted gamma rays and internal conversion electrons. The E0 transition strengths are found to be small and are consistent with the expectation for transitions from a K = 2 band to the K = 0 ground-state band in the axial rotor model. [ABSTRACT FROM AUTHOR]