# Lifetime Measurements of the $A^2\Pi_{1/2}$ and $A^2\Pi_{3/2}$ States in BaF

## TL;DR

This study precisely measures the lifetimes of specific excited states in BaF molecules using time-resolved laser-induced fluorescence, providing data crucial for electron EDM experiments.

## Contribution

It introduces a method with controlled systematic biases for accurate lifetime measurements of BaF excited states.

## Key findings

- Lifetimes of $A^2\Pi_{1/2}$ and $A^2\Pi_{3/2}$ states are 57.1 ns and 47.9 ns.
- The lifetime ratio aligns with excitation energy scaling.
- Results support BaF's suitability for electron EDM searches.

## Abstract

Time resolved detection of laser induced fluorescence from pulsed excitation of electronic states in barium monofluoride (BaF) molecules has been performed in order to determine the lifetimes of the $A^2\Pi_{1/2}$ and $A^2\Pi_{3/2}$ states. The method permits control over experimental parameters such that systematic biases in the interpretation of the data can be controlled to below $10^{-3}$ relative accuracy. The statistically limited values for the lifetimes of the $A^2\Pi_{1/2}(\nu=0)$ and $A^2\Pi_{3/2}(\nu=0)$ states are 57.1(3) ns and 47.9(7)~ns, respectively. The ratio of these values is in good agreement with scaling for the different excitation energies. The investigated molecular states are of relevance for an experimental search for a permanent electric dipole moment (EDM) of the electron in BaF.