Precision measurement and control of atomic hydrogen

Because of atomic hydrogen's simplicity, its energy levels can be precisely described by theory. This has made hydrogen an important atom in the development of quantum mechanics and quantum electrodynamics (QED). At present, assuming the QED calculations for hydrogen are correct, one can use hydrogen spectroscopy to determine the Rydberg constant and the proton-charge radius. A discrepancy of these constants determined through different transitions, or in different species, can indicate new physics. Unfortunately, spectroscopy of hydrogen is often limited by the temperature of the atomic sample, and laser cooling is very challenging since the wavelength of the radiation required is well into the vacuum ultraviolet (121.57 nm). In this talk, I will present new results where we load a metastable hydrogen beam into a moving optical lattice, which we then decelerate to control the motion of the atoms. This technique offers a robust means to slow atomic hydrogen with visible lasers, which could provide a platform for increased precision. In addition, I will discuss our measurement of the hydrogen 2S-8D two-photon transition performed in our group, which produces tension within the global dataset of precision hydrogen spectroscopy measurements.