Broadband velocity modulation spectroscopy of ThF+ for use in a measurement of the electron electric dipole moment

Abstract

A number of extensions to the Standard Model of particle physics predict a permanent electric dipole moment of the electron (eEDM) in the range of the current experimental limits. Trapped ThF+ will be used in a forthcoming generation of the JILA eEDM experiment. Here, we present extensive survey spectroscopy of ThF+ in the 700–1000nm spectral region, with the 700–900nm range fully covered using frequency comb velocity modulation spectroscopy. We have determined that the ThF+ electronic ground state is X3Δ1, which is the eEDM-sensitive state. In addition, we report high-precision rotational and vibrational constants for 14 ThF+ electronic states, including excited states that can be used to transfer and readout population in the eEDM experiment.