Structure of 186Ir and decoupling phenomena in doubly-odd deformed nuclei

States of ¹⁸⁶Ir, excited through several (HI, xn) reactions, were studied using in-beam γ-ray spectroscopy techniques. A completely new high-spin level scheme, comprising several rotational bands, is presented. The positive-parity ΔI = 2 ground-state band is possibly a first example of a hitherto unreported scheme called double decoupling associated with a proton and neutron both occupying $\text{Ω =}\text{1}\text{2}$ orbits of decoupling parameters larger than unity. A prominent ΔI = 1 negative-parity structure is interpreted as the $\text{π}\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{?}\text{ν}\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ band known in Tl isotopes but in a prolate-deformed situation.