Identification of Oblate Band in Odd-Odd ¹⁸⁴Au

High-spin states in ¹⁸⁴Au have been populated via the ¹⁴⁹Sm(²⁹Si, 4nγ) ¹⁸⁴Au reaction at a beam energy of 140 MeV. Three- or higher-fold γ-ray coincidences have been measured using the multidetector array of GASP. A rotational band built on the 11^- oblate πh^-1_11/2 vi^-1_13/2 structure has been newly observed, similar to those reported in ^186-194Au. This result extends the knowledge of shape coexistence to the currently lightest odd-odd Au isotope.