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arXiv · 0812.3509

New Measurement of the 2S Hyperfine Interval in Atomic Hydrogen

N. Kolachevsky·A. Matveev·J. Alnis·C. G. Parthey·S. G. Karshenboim·T. W. Haensch
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Abstract

An optical measurement of the 2S hyperfine interval in atomic hydrogen using two-photon spectroscopy of the 1S-2S transition gives a value of 177 556 834.3(6.7) Hz. The uncertainty is 2.4 times smaller than achieved by our group in 2003 and more than 4 times smaller than for any independent radio-frequency measurement. The specific combination of the 2S and 1S hyperfine intervals predicted by QED theory $D_{21}=8 f_{\rm HFS}({2S}) - f_{\rm HFS}({1S})=48 953(3)$ Hz is in good agreement with the value of 48 923(54) Hz obtained from this experiment.

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N. Kolachevsky, A. Matveev, J. Alnis, C. G. Parthey, S. G. Karshenboim, T. W. Haensch. 2008-12-18. New Measurement of the 2S Hyperfine Interval in Atomic Hydrogen. https://doi.org/10.1103/physrevlett.102.213002

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