Near-infrared LIF spectroscopy of HfF

TL;DR

This study used laser-induced fluorescence to explore the near-infrared spectrum of HfF, discovering new vibrational bands and providing detailed spectral data crucial for eEDM experiments.

Contribution

It reports the first unambiguous assignment of eight vibrational bands in HfF and improves measurements of ground state vibrational properties.

Findings

Discovered eight new vibrational bands in HfF spectrum.

Assigned bands to specific electronic transitions.

Provided improved measurements of vibrational spacing and anharmonicity.

Abstract

The molecular ion HfF$^+$ is the chosen species for a JILA experiment to measure the electron electric dipole moment (eEDM). Detailed knowledge of the spectrum of HfF is crucial to prepare HfF$^+$ in a state suitable for performing an eEDM measurement\cite{Leanhardt}. We investigated the near-infrared electronic spectrum of HfF using laser-induced fluorescence (LIF) of a supersonic molecular beam. We discovered eight unreported bands, and assign each of them unambiguously, four to vibrational bands belonging to the transition $[13.8]0.5 \leftarrow X1.5$, and four to vibrational bands belonging to the transition $[14.2]1.5 \leftarrow X1.5$. Additionally, we report an improved measurement of vibrational spacing of the ground state, as well as anharmonicity $\omega_e x_e$.