Hyperfine components of all rovibrational quadrupole transitions in the H$_{2}$ and D$_{2}$ molecules

Abstract

We report results of a theoretical investigation of hyperfine interactions in two homonuclear isotopologues of the hydrogen molecule: H 2 and D 2 . We present a set of hyperfine coupling constants: spin-rotation, spin-spin dipole and, in the case of the D 2 molecule, electric quadrupole coupling constants for all bound states of the two isotopologues in their ground electronic X 1 Σ + g state. We provide a list of positions and intensities of 220 997 hyperfine components of 16 079 rovibrational quadrupole transitions of the O, Q and S branches. The positions and intensities of the hyperfine components are necessary for a reliable interpretation of accurate measurements of rovibrational transition frequencies in H 2 and D 2 , which are used for tests of the quantum electrodynamics of molecules and searches for new physics beyond the Standard Model.

Hyperfine structure and electric quadrupole transitions in the deuterium molecular ion

“…[22] determined Q d with an uncertainty of 1.5 % from the hyperfine spectrum of a pure rotational transition of HD + . However, the most precise determination so far is from a comparison of experiment and theory for the neutral hydrogen molecules [18][19][20]. Their stated uncertainties, ranging from 1 × 10 −4 to 8 × 10 −4 , are so small that it is worthwhile to perform an independent measurement, using the molecular hydrogen ion HD + or D + 2 .…”