Publication

Rotational spectrum of the molecular ion NH+ as a probe for alpha and m(e)/m(p) variation

Beloy, 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 journalArticleAcademicpeer-review

  • K. Beloy
  • M. G. Kozlov
  • A. Borschevsky
  • A. W. Hauser
  • V. V. Flambaum
  • P. Schwerdtfeger

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.

Original languageEnglish
Article number062514
Number of pages7
JournalPhysical Review A
Volume83
Issue number6
Publication statusPublished - 30-Jun-2011
Externally publishedYes

    Keywords

  • ELECTRON MASS-RATIO, FUNDAMENTAL CONSTANTS, WAVE-FUNCTIONS, BASIS-SETS, SENSITIVITY, INVERSION, TH-229

ID: 31141679