Precision measurement of the fundamental vibrational frequencies of tritium-bearing hydrogen molecules: T${}_2$, DT, HT

Abstract

High-resolution coherent Raman spectroscopic measurements of all three tritium-containing molecular hydrogen isotopologues T${}_2$, DT and HT were performed to determine the ground electronic state fundamental Q-branch ($v=0\to 1,\Delta J=0$) transition frequencies at accuracies of $0.0005$ cm${}^{-1}$. An over hundred-fold improvement in accuracy over previous experiments allows the comparison with the latest ab initio calculations in the framework of Non-Adiabatic Perturbation Theory including nonrelativisitic, relativisitic and QED contributions. Excellent agreement is found between experiment and theory, thus providing a verification of the validity of the NAPT-framework for these tritiated species. While the transition frequencies were corrected for ac-Stark shifts, the contributions of non-resonant background as well as quantum interference effects between resonant features in the nonlinear spectroscopy were quantitatively investigated, also leading to corrections to the transition frequencies. Methods of saturated CARS with the observation of Lamb dips, as well as the use of continuous-wave radiation for the Stokes frequency were explored, that might pave the way for future higher-accuracy CARS measurements.

15 pages, 13 figures

References in corpus (7)

• Benchmarking theory with an improved measurement of the ionization and dissociation energies of H${}_2$
• Constraints on extra dimensions from precision molecular spectroscopy
• Complete ${\alpha }^{6}m$ corrections to the ground state of H${}_2$
• Assessment of molecular effects on neutrino mass measurements from tritium beta decay
• Lamb-dips and Lamb-peaks in the saturation spectrum of HD
• Reservoir spectroscopy of 5s5p ${}^3$P${}_2$ - 5s$n$d ${}^3$D${}_{1,2,3}$ transitions in strontium
• CARS spectroscopy of the ($v=0\to 1$) band in ${\mathrm{T}}_2$

Cited by in corpus (4)

• Nonrelativistic energy of tritium-containing hydrogen molecule isotopologues
• A Study of New Physics Searches with Tritium and Similar Molecules
• A Stimulated Raman Loss spectrometer for metrological studies of quadrupole lines of hydrogen isotopologues
• Precision measurement of quasi-bound resonances in H${}_2$ and the H + H scattering length