Precision Measurement of the 6S-7P_1/2 Cesium Transition Radial Matrix Element via Simultaneous Absorption Spectroscopy

Parity non-conservation in cesium electronic transitions has gathered significant interest over the past several decades, providing opportunities to probe the strength of the weak interaction. Through precise absorption strength measurements of classically permitted cesium transitions (6S-7P_1/2, 6S-7P_3/2) the strength of the classically forbidden parity non-conserving 6S-7S transition may be better understood. This measurement aims to refine the known strength of the 6S-7P_1/2 transition through simultaneous absorption strength measurements of both the 6S-7P_1/2 and 6S-7P_3/2 transitions. When these measurements are made simultaneously, the precise calculation of a radial matrix element is possible when the other radial matrix element is already precisely known. This methodology eliminates the need for knowledge of traditionally necessary parameters such as the density of the cesium cell and its length. Such parameters are difficult to determine experimentally. While work to verify our result continues, we have measured the ratio to better than 0.1% precision, more than 5 times better than past measurements.