Broadband velocity modulation spectroscopy of HfF^+: towards a   measurement of the electron electric dipole moment
  Precision spectroscopy of trapped HfF^+ will be used in a search for the permanent electric dipole moment of the electron (eEDM). While this dipole moment has yet to be observed, various extensions to the standard model of particle physics (such as supersymmetry) predict values that are close to the current limit. We present extensive survey spectroscopy of 19 bands covering nearly 5000 cm^(-1) using both frequency-comb and single-frequency laser velocity-modulation spectroscopy. We obtain high-precision rovibrational constants for eight electronic states including those that will be necessary for state preparation and readout in an actual eEDM experiment. 
Kevin C. Cossel, Daniel N. Gresh, Laura C. Sinclair, Tyler Coffey,   Leonid V. Skripnikov, Alexander N. Petrov, Nikolai S. M...
physics.atom-ph physics.chem-ph