Measurement of the 6p2P3/2state lifetime in atomic cesium

We present a precision experimental test of atomic many-body theory that is currently applied to the interpretation of recent parity-nonconservation experiments in atomic cesium. We report the first measurement of the ${}_{}{}^{133}{}_{}{}^{}\mathrm{Cs}$ 6p ${}_{}{}^2{}_{}{}^{}$ ${\mathit{P}}_{3/2}$ state lifetime using resonant diode-laser excitation of a fast atomic beam. The lifetime result of 30.55±0.27 ns determines the absorption oscillator strength for the 6s ${}_{}{}^2{}_{}{}^{}$ ${\mathit{S}}_{1/2}$–6p ${}_{}{}^2{}_{}{}^{}$ ${\mathit{P}}_{3/2}$ transition in cesium to be 0.7133±0.0064, and establishes the accuracy of recent relativistic many-body calculations of the dipole transition matrix element to 0.5%.