Sensitivity of the H3O+ inversion-rotational spectrum to changes in m_e/m_p

Abstract

Quantum mechanical tunneling inversion transition in ammonia NH3 is actively used as a sensitive tool to study possible variations of the electron-to-proton mass ratio, mu = m_e/m_p. The molecule H3O+ has the inversion barrier significantly lower than that of NH3. Consequently, its tunneling transition occurs in the far-infrared (FIR) region and mixes with rotational transitions. Several such FIR and submillimiter transitions are observed from the interstellar medium in the Milky Way and in nearby galaxies. We show that the rest-frame frequencies of these transitions are very sensitive to the variation of mu, and that their sensitivity coefficients have different signs. Thus, H3O+ can be used as an independent target to test hypothetical changes in mu measured at different ambient conditions of high (terrestrial) and low (interstellar medium) matter densities. The environmental dependence of mu and coupling constants is suggested in a class of chameleon-type scalar field models - candidates to dark energy carrier.

8 pages, 2 figures, accepted to ApJ; v2: reformatted for ApJ and discussion of systematics significantly extended

Cited by in corpus (17)

• The status of varying constants: a review of the physics, searches and implications
• Laser-Cooled Polyatomic Molecules for Improved Electron Electric Dipole Moment Searches
• Methanol as a tracer of fundamental constants
• Perspective: Tipping the scales - search for drifting constants from molecular spectra
• New constraint on cosmological variation of the proton-to-electron mass ratio from Q0528-250
• Constraining fundamental constant evolution with HI and OH lines
• Microwave and submillimeter molecular transitions and their dependence on fundamental constants
• Molecular ions in the O-rich evolved star OH231.8+4.2: HCO${}^{+}$,H${}^{13}$CO${}^{+}$ and first detection of SO${}^{+}$, N${}_2$H${}^{+}$, and H${}_3$O${}^{+}$
• Rotational spectrum of molecular ion NH^+ as a probe for alpha- and m_e/m_p-variation
• Modular cryostat for ion trapping with surface-electrode ion traps
• ExoMol line lists -- XL. Ro-vibrational molecular line list for the hydronium ion (H${}_3$O${}^{+}$)
• Methyl mercaptan (CH3SH) as a probe for $\mu$ variation
• Sensitivity of the isotopologues of hydronium to variation of the electron-to-proton mass ratio
• Accurate prediction of H${}_3$O${}^{+}$ and D${}_3$O${}^{+}$ sensitivity coefficients to probe a variable proton-to-electron mass ratio
• Diatomic rovibronic transitions as potential probes for proton-to-electron mass ratio across cosmological time
• Sensitivity of microwave transition in H2O2 to variation of the electron-to-proton mass ratio
• Molecular Quantum Control Algorithm Design by Reinforcement Learning