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Published on: February 14, 2014
Ramsey Spectroscopy of the 2S_{1/2} Hyperfine Interval in Atomic Hydrogen
R G Bullis1, C Rasor1, W L Tavis1
1Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA.
Abstract:
The 2S_{1/2} hyperfine interval in atomic hydrogen was measured using Ramsey spectroscopy with a thermal beam cooled to cryogenic temperatures. The measured value is 177 556 838.87(85) Hz, which represents the most precise determination of this interval to date. The 1S_{1/2} hyperfine interval f(1S_{1/2}) and the 2S_{1/2} hyperfine interval f(2S_{1/2}) can be combined to give the quantity D_{21}=8f(2S_{1/2})-f(1S_{1/2}), which mostly eliminates uncertainty due to nuclear structure effects and is well described by bound-state quantum electrodynamics. Using the value of f(2S_{1/2}) from this work gives a value of D_{21}^{expt}=48 959.2(6.8) Hz, which is in agreement with the theoretical value of D_{21}^{Theory}=48 954.1(2.3) Hz.
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