Lifetime of the 2 {sup 3}P{sub 0} state of He-like {sup 197}Au

An experiment has been performed at the Gesellschaft f\"ur Schwerionenforschung accelerator facility using a beam-foil time-of-flight technique with a newly developed chemical vapor deposition diamond particle detector to measure the lifetime of the $2{}^{3}{P}_{0}$ state, $\ensuremath{\tau}(2{}^{3}{P}_{0}),$ of the two-electron ion ${}^{197}{\mathrm{Au}}^{77+}$ (He-like gold) with the result $\ensuremath{\tau}(2{}^{3}{P}_{0})=22.16(0.81)$ ps. The mechanism for the decay of this state is by a hyperfine-induced radiative transition to the $1{}^{1}{S}_{0}$ ground state (hyperfine quenching). The lifetime is therefore determined by a number of fundamental atomic and nuclear parameters not normally involved in radiative decay of allowed transitions. The experimental result is compared to several theoretical calculations.