Laser-assisted nuclear decay spectroscopy of $^{176,177,179}$Au

A study of the laser-ionized and mass-separated neutron-deficient isotopes $^{176,177,179}$Au was performed using the Resonance Ionization Laser Ion Source and the Windmill detection setup at ISOLDE, CERN. New and improved data on complex fine-structure α decays of the three isotopes were deduced, providing insight into the low-lying levels in the daughter nuclei $^{172,173,175}$Ir. New information on the properties of β-decay daughter products $^{177,179}$Pt was also obtained. From the first in-source laser spectroscopy measurements of the hyperfine structure in the atomic 267.6-nm transition of 176Au, the nuclear magnetic moments for both high- and low-spin α-decaying states were deduced. Together with the values determined from the additivity relations, they were used to propose the most probable spins and configurations for both states. The α-decay branching ratios were determined as $b_{\alpha}$ $\left (^{176}\textrm{Au}^{ls}\right)=58(5)$% and $b_{\alpha}$ $(^{176} \textrm{Au}^{hs})=29(5)$%.