Measurement of the Stark shift of the 6s$^{2}$S$_{1/2}$ $\to$ 7p$^{2}$P$_{\mathrm{J}}$ transitions in atomic cesium

We report measurements of the Stark shift of the cesium 6s$^{2}$S$_{1/2} \to $ 7p$^{2}$P$_{1/2}$ and 6s$^{2}$S$_{1/2}$ $\to $ 7p$^{2}$P$_{3/2}$ transitions at $\lambda = $ 459 and 456 nm, respectively, in an atomic beam. From these measurements, we determine the static scalar polarizability for both 7P$_{\mathrm{J}}$ states and the tensor polarizability for the 7P$_{3/2}$ state. The fractional uncertainty of the scalar polarizabilities is $\sim $0.18{\%}, while that of the tensor term is 0.7{\%}. These measurements allow a precise determination of the reduced radial matrix elements \textless 7P$_{1/2}$\textbar \textbar r\textbar \textbar 6D$_{3/2}$\textgreater $=$ 17.92 (3) a$_{\mathrm{0}}$ and \textless 7P$_{3/2}$\textbar \textbar r\textbar \textbar 6D$_{5/2}$\textgreater $=$ 24.28 (6) a$_{\mathrm{0}}$, providing a sensitive test and critical confirmation of theoretical models of the Cs atom, which has played a central role in parity nonconservation measurements.