Affiliation: | a Institut für Kernphysik, Universität zu Köln, Zülpicher Str. 77, 50937, Köln, Germany b Institut für Strahlenphysik, Universität Stuttgart, Allmandring 3, 70569, Stuttgart, Germany c Departments of Chemistry and Physics & Astronomy, University of Kentucky, Lexington, KY 40506-0055, USA d Institut für Strahlen- und Kernphysik, Universität Bonn, Nußallee 14-16, 53115, Bonn, Germany |
Abstract: | Following the successful identification of mixed-symmetric one- and two-phonon states in the N=52 nuclei 94Mo and 96Ru, we have performed a photon scattering experiment on the N=52 isotone 92Zr. Experimental data and shell model calculations show that both, single particle and collective degrees of freedom are present in the low-lying levels of 92Zr. The second excited quadrupole state shows the signatures of the one-phonon mixed-symmetric 2+ state, while calculations and data indicate an almost pure neutron configuration for the 2+1 state, in contradiction with the F-spin symmetric limit. Furthermore, two strong dipole excitations, which are candidates for the two-phonon quadrupole–octupole coupled E1 excitation and for the mixed-symmetric 1+ two-phonon state, were observed. |