Precision Measurements and Precision Spectroscopy

We report the most recent progress on high precision spectroscopic measurements from the Raven Lab at Smith College.  We report on excited-state spectroscopy measurements in oxygen, nitrogen, and beryllium. Combined with future theoretical predictions and experimental results, this work will serve as a test for quantum electrodynamics. For oxygen, we report the absolute frequencies of nine transitions between the 2s²2p³(⁴S_o)3p ⁵P states and the 2s²2p³(⁴S₀)3d ⁵D^o states and three transitions between the 2s²2p³(⁴S_o)3s ³S^o and the 2s²2p³(⁴S_o)3p ³P states. For nitrogen, we report the transition frequencies between the 2s²2p²(³P)3p ²S^o_1/2 states and the 2s²2p²(³P)3d ²P_½ states.  For beryllium, we report on the absolute energy of the 2s3s ¹S state and progress on measuring other states. The nitrogen and beryllium measurements, which have angular momentum in the lower state, are limited in their precision because of merged hyperfine structure. We call for additional theoretical support in modeling these spectrum, and note possible experimental methods to further reduce the uncertainty in these measurements.

Funding acknowledgement

This material is based upon work supported by the National Science Foundation under Grant No. 2110311.