Level structure ofZr83

The level structure of ${}_{}{}^{83}{}_{}{}^{}\mathrm{Zr}$ was investigated via the fusion-evaporation reaction ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$ ${(}^{32}$S,2pn${)}^{83}$Zr at beam energies between 105 and 120 MeV using in-beam γ-ray spectroscopy techniques. γ transitions from the decay of ${}_{}{}^{83}{}_{}{}^{}\mathrm{Zr}$ were unambiguously identified by means of recoil-γ, neutron-γ, and x-ray-γ coincidences. The decay scheme was constructed on the basis of Compton suppressed γ-γ coincidences, delayed γ-γ coincidences, and angular distribution measurements. A total of 34 transitions were identified connecting 26 new energy levels and the previously known ground state. The lifetimes of two low-lying isomeric states were determined. A decoupled positive parity band built on the odd $g_{9/2}$ neutron configuration was observed up to spin (37/2ħ with the first band crossing due to proton alignment showing a sharp backbend at ħω=0.5 Mev. A strongly coupled negative parity band based on a ${(5/2\mathrm{}}^{\mathrm{-}}$ bandhead was observed up to spin (35/2ħ. The angular momentum alignment is discussed and compared to neighboring nuclei. A theoretical analysis was performed using the Woods-Saxon cranking model. The results of the calculation are consistent with the experimental findings for ${}_{}{}^{83}{}_{}{}^{}\mathrm{Zr}$ and its neighbors. Triaxial shapes are predicted for all observed bands in ${}_{}{}^{83}{}_{}{}^{}\mathrm{Zr}$. At higher angular momenta a transition to well-deformed prolate bands involving the $h_{11/2}$ intruder orbitals is expected.