Probing Triaxiality Beyond the Proton Drip Line: Spectroscopy of Tm147

Two triaxial states of the proton-decaying nucleus $^{147}\mathrm{Tm}$ were studied via a comparison of experimental data to results obtained through nonadiabatic quasiparticle calculations. The experimental data were collected in a recoil-decay tagging study using the vacuum-mode recoil separator MARA coupled with the JUROGAM3 $\ensuremath{\gamma}$-ray spectrometer. The previously proposed level scheme above the triaxial $11/{2}^{\ensuremath{-}}$ $(\ensuremath{\pi}{h}_{11/2})$ ground state was confirmed, and the level structure was expanded to cover the states above the weakly populated proton-emitting $5/{2}^{+}$ $(\ensuremath{\pi}{d}_{5/2})$ isomeric state. It was found that the isomeric state is also triaxial, and possibly more deformed than the ground state.