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Testing Quantum Electrodynamics in the Lowest Singlet State of Neutral Beryllium-9
E C Cook1, A D Vira1, C Patterson1
1Physics Department, Smith College, Northampton, Massachusetts 01063, USA.
Abstract:
We report spectroscopic results on the 2s2p^{1}P_{1} state in neutral atomic beryllium-9. The absolute frequency for the center of gravity is determined to be 42 565.4501(13) cm^{-1}, a factor of 130 more precise than the previous experimental measurement. The result is in agreement with and a factor of 8 more precise than the current best theoretical estimate of 42 565.441(11) cm^{-1}, which was calculated including the effects of quantum electrodynamics. Because of the large natural linewidth of the transition, the hyperfine constants were not able to be extracted to high precision.
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