Resonance-Narrowed-Lamb-Shift Measurement in Hydrogen,n=3

Abstract
A new measurement of the Lamb shift in the n=3 state of atomic hydrogen is reported. The experiment was performed in zero magnetic field with a fast hydrogen beam. The radio-frequency spectroscopy measurements were made with both a single oscillating field and two separated oscillating fields. The final result for the Lamb shift was S(H, n=3)=(314.819±0.048) MHz. In a further experiment, the separated-oscillating-field technique was used to narrow the resonance so that the linewidth was less than the natural linewidth.