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

Abstract

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 X1∑+ 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 X1++, 3δ 1, 3δ2 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 X1∑+ and 3δ 1 levels are found to be less favorable for the proposed studies of the fine structure constant. © 2011 American Institute of Physics.