Accurate Prediction of the Ammonia Probes of a Variable Proton-to-Electron Mass Ratio

Abstract

A comprehensive study of the mass sensitivity of the vibration-rotation-inversion transitions of ${}^{14}$NH${}_3$, ${}^{15}$NH${}_3$, ${}^{14}$ND${}_3$, and ${}^{15}$ND${}_3$ is carried out variationally using the TROVE approach. Variational calculations are robust and accurate, offering a new way to compute sensitivity coefficients. Particular attention is paid to the $\Delta k=\pm 3$ transitions between the accidentally coinciding rotation-inversion energy levels of the ${\nu }_2=0^{+},0^{-},1^{+}$ and $1^{-}$ states, and the inversion transitions in the ${\nu }_4=1$ state affected by the "giant" $l$-type doubling effect. These transitions exhibit highly anomalous sensitivities, thus appearing as promising probes of a possible cosmological variation of the proton-to-electron mass ratio $\mu$. Moreover, a simultaneous comparison of the calculated sensitivities reveals a sizeable isotopic dependence which could aid an exclusive ammonia detection.

18 pages, 2 figures, 10 tables

References in corpus (10)

• A Dust-Obscured Massive Maximum-Starburst Galaxy at a Redshift of 6.34
• Strong Limit on a Variable Proton-to-Electron Mass Ratio from Molecules in the Distant Universe
• Enhanced sensitivity to time-variation of m_p/m_e in the inversion spectrum of ammonia
• A theoretical room-temperature line list for 15NH3
• The detection of the (J,K)=(18,18) line of NH3
• Submillimeter water and ammonia absorption by the peculiar z~0.89 interstellar medium in the gravitational lens of the PKS 1830-211 system
• Widespread Rotationally-Hot Hydronium Ion in the Galactic Interstellar Medium
• Preparation of an ultra-cold sample of ammonia molecules for precision measurements
• Stringent bounds to spatial variations of the electron-to-proton mass ratio in the Milky Way
• Sensitivity of the isotopologues of hydronium to variation of the electron-to-proton mass ratio

Cited by in corpus (3)

• Perspective: Accurate ro-vibrational calculations on small molecules
• Symmetry adapted ro-vibrational basis functions for variational nuclear motion calculations: TROVE approach
• Transformation Properties under the Operations of the Molecular Symmetry Groups $G_{36}$ and $G_{36}\text{(EM)}$ of Ethane ${\text{H}}_3{\text{CCH}}_3$