Identification of a New Four-Quasiparticle State in Odd-Odd 186Au

The high-spin level structureof 186Au is re-investigated by means of in-beam γ-ray spectroscopy via the 172Yb(19F, 5nγ)186Au reaction. The oblatebands previously reported are revised and extended to higher-spin states. A new Iπ = (20+) excited state has been identified and assigned to the πh−111/2 ⊗ νi−213/2h−19/2 configuration. The total Routhiansurface and cranked shell modelcalculations suggest that the πh−111/2 ⊗ νi−213/2h−19/2 band in 186Au has a non-axial deformation.