Centrifugal correction to hyperfine structure constants in the ground state of lead monofluoride, PbF

TL;DR

This paper improves the theoretical modeling of the hyperfine structure in lead monofluoride by determining centrifugal correction parameters, enabling better agreement with high-precision microwave spectroscopy data.

Contribution

It introduces centrifugal correction parameters for hyperfine constants in PbF, derived from experimental data and ab initio calculations, enhancing spectral interpretation accuracy.

Findings

Centrifugal corrections are essential for accurate hyperfine structure modeling.

The corrected model matches experimental transition energies.

First-principles calculations support the fitted parameters.

Abstract

The sensitivity of the PbF molecule to the electron electric dipole moment has motivated detailed microwave spectroscopy. Previous theoretical approaches cannot fully explain the spectra. In turn, the explanation from "first principles" is very important both for molecular theory and for confirmation of the correctness of the interpretation of experimental data obtained with high precision. All of these issues are decisively addressed here. We have determined centrifugal correction parameters for hyperfine structure constants, both on lead and fluorine nuclei, of the $X^2\Pi_{1/2}$ state of lead monofluoride. These parameters were obtained by fitting experimentally observed pure rotational transitions and from {\it ab initio} calculations. We show that taking this correction into account is required to reproduce the experimental transition energies obtained in [Phys. Rev. A 84, 022508 (2011)].