HD分子のラム・ディップ測定による陽子・電子質量比の決定に向けた精密分光研究
This study investigates precision spectroscopy of the hydrogen deuteride (HD) molecule as a means of testing quantum electrodynamics (QED) and determining fundamental physical constants. Using a frequency-comb-stabilized cavity ring-down spectrometer, the Lamb-dip spectrum of the R(1) rovibrational line in the HD overtone band was recorded for the first time. The measured line center frequency was 217 105 182.79 ± 0.03 (statistical) ± 0.08 (systematic) MHz, corresponding to a relative uncertainty of 4×10⁻¹⁰, representing the most precise rovibrational transition measurement in the ground electronic state of any hydrogen molecule to date. Theoretical predictions incorporating QED corrections up to order mₑα⁶ were computed for both the R(1) line and the HD dissociation energy. Discrepancies between theory and experiment highlight the necessity of fully accounting for nonadiabatic effects. Should theoretical accuracy reach the experimental level, this measurement framework could enable determination of the proton-to-electron mass ratio at a precision of 1.3 parts per billion.
The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).
See also:
https://h2-papers.org/en/papers/29756862