Abstract
The → and → transition frequencies ( and , respectively) in positronium have been measured for the first time and an improved measurement of the → transition frequency () has been made. The results =18504.1±10.0±1.7 MHz, =13001.3±3.9±0.9 MHz, and =8619.6±2.7±0.9 MHz are in reasonable agreement with the predictions of quantum electrodynamics which are, to order Ry, ()=18496.1 MHz, ()=13010.9 MHz, and ()=8625.2 MHz. More precise measurements are planned to test the, as yet uncalculated, order Ry corrections.
- Received 10 February 1987
DOI:https://doi.org/10.1103/PhysRevLett.58.1833
©1987 American Physical Society