Atoms 2017, 5(4), 38; https://doi.org/10.3390/atoms5040038
THz/Infrared Double Resonance Two-Photon Spectroscopy of HD+ for Determination of Fundamental Constants
Laboratoire PhLAM, CNRS UMR 8523, 59655 Villeneuve d’Ascq, France
Received: 1 September 2017 / Revised: 1 October 2017 / Accepted: 6 October 2017 / Published: 12 October 2017
(This article belongs to the Special Issue High Precision Measurements of Fundamental Constants)
Abstract
A double resonance two-photon spectroscopy scheme is discussed to probe jointly rotational and rovibrational transitions of ensembles of trapped HD+ ions. The two-photon transition rates and lightshifts are calculated with the two-photon tensor operator formalism. The rotational lines may be observed with sub-Doppler linewidth at the hertz level and good signal-to-noise ratio, improving the resolution in HD+ spectroscopy beyond the 10−12 level. The experimental accuracy, estimated at the 10−12 level, is comparable with the accuracy of theoretical calculations of HD+ energy levels. An adjustment of selected rotational and rovibrational HD+ lines may add clues to the proton radius puzzle, may provide an independent determination of the Rydberg constant, and may improve the values of proton-to-electron and deuteron-to-proton mass ratios beyond the 10−11 level. View Full-TextKeywords:
two-photon spectroscopy; hyperfine structure; two-photon lightshift; trapped ions; Rydberg constant; proton-to-electron mass ratio; deuteron-to-proton mass ratio; proton radius; deuteron radius
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Constantin, F.L. THz/Infrared Double Resonance Two-Photon Spectroscopy of HD+ for Determination of Fundamental Constants. Atoms 2017, 5, 38.
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