Rotational level spacings in HD from vibrational saturation spectroscopy

Autor: Cozijn, F. M. J., Diouf, M. L., Hermann, V., Salumbides, E. J., Schlösser, M., Ubachs, W.
Rok vydání: 2022
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevA.105.062823
Popis: The R(1), R(3) and P(3) ro-vibrational transitions in the (2-0) overtone band of the HD molecule are measured in Doppler-free saturation using the technique of NICE-OHMS spectroscopy. For the P(3) line, hitherto not observed in saturation, we report a frequency of $203\,821\,936\,805\,(60)$ kHz. The dispersive line shapes observed in the three spectra show strong correlations, allowing for extraction of accurate information on rotational level spacings. This leads to level spacings of $\Delta_{(J=3)-(J=1)}= 13\,283\,245\,098\,(30)$ kHz in the $v=0$ ground state, and $\Delta_{(J=4)-(J=2)}= 16\,882\,368\,179\,(20)$ kHz in the $v=2$ excited vibration in HD. These results show that experimental values for the rotational spacings are consistently larger than those obtained with advanced ab initio theoretical calculations at 1.5$\sigma$, where the uncertainty is determined by theory. The same holds for the vibrational transitions where systematic deviations of 1.7-1.9$\sigma$ are consistently found for the five lines accurately measured in the (2-0) band.
Comment: 8 pages, 5 figures, Physical Review A, accepted
Databáze: arXiv