Measurement of the branching fractions and lifetime of the $5D_{5/2}$ level of Ba$^+$

TL;DR

This paper reports precise measurements of the branching fractions and lifetime of the $5D_{5/2}$ level in Ba$^+$, providing the first experimental transition rates and confirming theoretical predictions.

Contribution

The study provides the first experimental determination of transition rates from the $5D_{5/2}$ level in Ba$^+$, including branching fractions and lifetime with improved accuracy.

Findings

Branching fraction to ground state: 0.846(25)

Lifetime of $5D_{5/2}$: 31.2(0.9) seconds

Good agreement with theoretical transition rate predictions

Abstract

We present a measurement of the branching fractions for decay from the long-lived $5D_{5/2}$ level in \Ba. The branching fraction for decay into the $6S_{1/2}$ ground state was found to be $0.846(25)_{\mathrm{stat}}(4)_{\mathrm{sys}}$. We also report an improved measurement of the $5D_{5/2}$ lifetime, $\tau_{5D_{5/2}}=31.2(0.9)$~s. Together these measurements provide the first experimental determination of transition rates for decay out of the $5D_{5/2}$ level. The low ($<7 \times 10^{-12}$~Torr) pressure in the ion trap in which these measurements were made simplified data acquisition and analysis. Comparison of the experimental results with theoretical predictions of the transition rates shows good agreement.