International Conference on Precision Physics and Fundamental Physical Constants (FFK-2019)

The hydrogen n=2 Lamb shift (and the proton size) and helium n=2 fine structure (and the fine-structure constant)

12 Jun 2019, 09:30

30m

Balaton Limnological Research Institute of the Hungarian Academy of Sciences

Session 7: Fundamental constants, atomic properties

Speaker

E. A. Hessels (York University)

Description

We report on new measurements of the $n$$=$2 Lamb shift in atomic hydrogen using the new frequency-offset separated-oscillatory-fields (FOSOF) technique. This measurement can be used to determine the proton rms charge radius, and therefore contributes to the resolution of the proton size problem. A measurement of the $J$$=$1 to $J$$=$2 $n$=2 triplet-P fine structure interval is measured with unprecedented accuracy, again using the FOSOF technique. This interval, along with a similar measurement of the $J$$=$0 to $J$$=$1 interval (which we are presently performing) and along with sufficiently precise QED theory will allow for a precise determination of the fine-structure constant.