Rotational spectrum of the molecular ion NH+ as a probe for alpha and m(e)/m(p) variationBeloy, K., Kozlov, M. G., Borschevsky, A., Hauser, A. W., Flambaum, V. V. & Schwerdtfeger, P., 30-Jun-2011, In : Physical Review A. 83, 6, 7 p., 062514.
Research output: Contribution to journal › Article › Academic › peer-review
We identify the molecular ion NH+ as a potential candidate for probing variations in the fine-structure constant alpha and electron-to-proton mass ratio mu. NH+ has an anomalously low-lying excited (4)Sigma(-) state, being only a few hundred cm(-1) above the ground (2)Pi state. Being a light molecule, this proximity is such that rotational levels of the respective states are highly intermixed for low angular momenta. We find that several low-frequency transitions within the collective rotational spectrum experience enhanced sensitivity to alpha and mu variation. This is attributable to the close proximity of the (2)Pi and (4)Sigma(-) states, as well as the ensuing strong spin-orbit coupling between them. Suggestions that NH+ may exist in interstellar space and recent predictions that trapped-ion precision spectroscopy will be adaptable to molecular ions make NH+ a promising system for future astrophysical and laboratory studies of alpha and mu variation.
|Number of pages||7|
|Journal||Physical Review A|
|Publication status||Published - 30-Jun-2011|
- ELECTRON MASS-RATIO, FUNDAMENTAL CONSTANTS, WAVE-FUNCTIONS, BASIS-SETS, SENSITIVITY, INVERSION, TH-229