High-precision spectroscopy in neutral beryllium-9

We report on spectroscopic measurement progress for a variety of states in neutral beryllium-9.~ Measurements include the absolute transition frequencies and hyperfine constants for the 2s2p 1P1, 2s2p 3P1, and 2s3d 1D2 states.~ Our experimental result for the absolute frequency from the ground state to the 2s2p 1P1 state is in agreement with recent theoretical predictions that include the effects of quantum electrodynamics[1].~ We also present the first hyperfine spectra for the 2s2p 1P1 and the 2s3d 1D2 states. [1]Puchalski et al. PRA 87, 030502(R) (2013)