Investigation of low-spin states in Zr92 with the (n,n'γ) reaction

Excited low-spin states of Zr92 have been studied with the (n,n'γ) reaction. Comprehensive data on the electromagnetic decay of states with excitation energies up to about 3.8 MeV in particular, lifetimes, γ-ray branching ratios, multipole mixing ratios, and absolute transition strengths have been obtained. The detailed spectroscopic information about the low-spin level scheme enables us to address the predominant proton-neutron symmetry for low-spin states of Zr92. These data are compared to those of corresponding states in the N=52 isotone Mo94 and to a shell model calculation using Sr88 as an inert core. However, neither a purely collective picture nor the restricted shell model calculation yields a fully satisfactory description of the observed structures. © 2005 The American Physical Society.