Hyperfine structure of quadrupole rovibrational transitions in tritium-bearing hydrogen isotopologues

Abstract

We perform a theoretical investigation of hyperfine interactions in the tritium-bearing isotopologues of the hydrogen molecule: HT, DT and T2. We report a set of hyperfine coupling constants: spin-rotation, spin-spin dipole and, in the case of the DT isotopologue, electric quadrupole coupling constants for all bound states of the three isotopologues in their ground electronic states. We determine positions and intensities of 656 217 hyperfine components of 38 971 quadrupole rovibrational transitions from 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 tritium-bearing isotopologues of hydrogen, which are useful for tests of quantum electrodynamics for molecules and searches for new physics beyond the Standard Model.