Improved dipole transition strengths in Ba$^{+}$ from Ba Rydberg spectroscopy

Recent determinations of the dipole transition strengths between the 6$^{2}$S$_{1/2}$ ground state of Ba$^{+}$ and the 6$^{2}$P$_{1/2}$ and 6$^{2}$P$_{3/2}$ levels combined two types of Rydberg Ba fine structure measurements, perturbed binding energy measurements and K-splitting measurements, to determine both transition strengths and their ratio more precisely than allowed by existing lifetime measurements [1]. The precision of these results, however, was limited not by the Rydberg measurements, but by uncertainty in the calculation of the polarizability of Ba$^{2+}$ which had not been measured directly. The recently reported measurement of this polarizability [2] allows an improved analysis of existing Rydberg data and reduces the uncertainty in the inferred transition strengths.\\[4pt] [1] Shannon L. Woods, S. R. Lundeen, and Erica L. Snow, Phys. Rev. A 80, 042516 (2009)\\[0pt] [2] Erica L. Snow, et. al. private communication.