Progress Towards Measurement of the Electron Electric Dipole Moment Using the PbF Molecule: Measurement of Hyperfine Splittings

The lead monofluoride molecule provides for a 1000- to 10,000- fold improvement in sensitivity to an electron electric dipole moment (e-EDM) over atomic-based measurements. An understanding of details of the electronic structure of the ground state of PbF is critical to quantify this sensitivity. The hyperfine constants of the molecule provide an unique test of our understanding of the ground-state wave function of the molecule. Here we present a comparison of our latest measurements to previous predictions.