Measurement of the radial matrix elements of the 6s $^{2}$S$_{1/2\, }\to $ 7p $^{2}$P$_{J}$ transitions in atomic cesium*

We report measurements of the absorption strength of the cesium 6s $^{2}$S$_{1/2\, }\to $ 7p $^{2}$P$_{3/2}$ and the 6s $^{2}$S$_{1/2\, }\to $ 7p $^{2}$P$_{1/2}$ transitions at $\lambda =$ 456 nm and 459 nm, respectively. We simultaneously measure the absorption strength on the Cs D$_{1}$ line (6s $^{2}$S$_{1/2\, }\to $ 6p $^{2}$P$_{1/2})$ at $\lambda =$ 894 nm, for which the electric dipole transition moment is precisely known, allowing us to precisely determine the reduced dipole matrix elements for these two lines. Our results are $\langle $7P$_{3/2}$\textbar \textbar r\textbar \textbar 6S$_{1/2}\rangle \quad =$ 0.5780 (7) a$_{0}$ and $\langle $7P$_{1/2}$\textbar \textbar r\textbar \textbar 6S$_{1/2}\rangle \quad =$ 0.2789 (16) a$_{0}$, with fractional uncertainties of 0.12{\%} and 0.6{\%}, respectively. These new values allow a more precise determination of the scalar polarizability for the Cs 6s $^{2}$S$_{1/2\, }\to $ 7s $^{2}$S$_{1/2}$ transition, which in turn leads to a more precise value of the vector polarizability for this same transition. The vector polarizability has played a critical role in measurements of the parity nonconserving transition amplitude E$_{PNC}$ in cesium. This revised value of the vector polarizability is in reasonable agreement with the value determined through the nuclear spin dependent component of the transition magnetic dipole moment.