AN ELECTRONIC SPECTROSCOPIC STUDY OF A MOLECULAR BEAM SAMPLE OF YbOCH3

Ytterbium monofluoride, YbF, has long been used as a venue in attempts to measure the electron electric dipole moment (eEDM) \footnote{Hudson, J. J.; Sauer, B. E.; Tarbutt, M. R.; Hinds, E. A., Measurement of the Electron Electric Dipole Moment Using YbF Molecules. Phys. Rev. Lett. 2002, 89 (2), 023003/1-023003/4.}$^{,}$\footnote{Tarbutt, M. R.; Sauer, B. E.; Hudson, J. J.; Hinds, E. A., Design for a fountain of YbF molecules to measure the electron's electric dipole moment. New J. Phys. 2013, 15 (May), 053034/1-053034/17.}. As pointed out by Kozyryev and Hutzler \footnote{Kozyryev, I.; Hutzler, N. R., Precision measurement of time-reversal symmetry violation with laser-cooled polyatomic molecules. arXiv.org, e-Print Arch., Phys. 2017, 1-11.}, Yb containing symmetric top molecules are expected to exhibit enhanced sensitivity for EDM measurements, relative to \chem{YbF}. This is largely due to the ease of polarization of the K $\neq$ 1 rotational levels. Here we report on our initial molecular beam studies of the heretofore unknown molecules \chem{YbOCH_3} and \chem{YbOCD_3}. Broad survey scans using two dimensional (excitation vs dispersed fluorescence) spectroscopy in the 600-480 nm range were recorded. An intense band detected near 579 nm is assigned to the origin band of the electronic transition of \chem{YbOCH_3}. The high-resolution ($\sim$ 30 MHz) laser induced fluorescence (LIF) spectrum of this band was recorded both field-free and in the presence of a static electric field. The dispersed fluorescence resulting from the excitation of rotationally resolved branch features has been analyzed to produce fluorescence branching ratios. Implications for planned EDM measurements will be presented