Communication: Spectroscopic measurements for HfF~+ of relevance to the investigation of fundamental constants

摘要

The properties of the HfF~+ cation are thought to be well-suited for investigations of the electron electric dipole moment (eEDM) and temporal variations of the fine structure constant. Precision spectroscopic measurements involving the X~1∑~+ and low-lying ~3δ _1 states have been proposed to measure both. Due to the lack of data for HfF~+, the design of these experiments has relied entirely on the predictions of electronic structure calculations. Spectroscopic characterizations of the X~1+~+, ~3δ _1, ~3δ_2 and ~3δ _3 states are reported. The results further support the contention that HfF~+ is a viable candidate for eEDM measurements. The spacings between adjacent X~1∑~+ and ~3δ _1 levels are found to be less favorable for the proposed studies of the fine structure constant.