Rotational spectrum of the molecular ion NH+ as a probe for α and me/mp variation

K. Beloy, M. G. Kozlov, A. Borschevsky, Andreas Hauser, V. V. Flambaum, P. Schwerdtfeger

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We identify the molecular ion NH+ as a potential candidate for probing variations in the fine-structure constant α and electron-to-proton mass ratio μ. NH+ has an anomalously low-lying excited 4Σ- state, being only a few hundred cm-1 above the ground 2Π 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 α and μ variation. This is attributable to the close proximity of the 2Π and 4Σ- 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 α and μ variation.

Original languageEnglish
Article number062514
JournalPhysical review / A
Volume83
Issue number6
DOIs
Publication statusPublished - 30 Jun 2011
Externally publishedYes

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rotational spectra
molecular ions
proximity
probes
interstellar space
mass ratios
suggestion
astrophysics
angular momentum
fine structure
low frequencies
orbits
protons
sensitivity
predictions
spectroscopy
molecules
ions
electrons

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Fields of Expertise

  • Advanced Materials Science

Cite this

Beloy, K., Kozlov, M. G., Borschevsky, A., Hauser, A., Flambaum, V. V., & Schwerdtfeger, P. (2011). Rotational spectrum of the molecular ion NH+ as a probe for α and me/mp variation. Physical review / A, 83(6), [062514]. https://doi.org/10.1103/PhysRevA.83.062514

Rotational spectrum of the molecular ion NH+ as a probe for α and me/mp variation. / Beloy, K.; Kozlov, M. G.; Borschevsky, A.; Hauser, Andreas; Flambaum, V. V.; Schwerdtfeger, P.

In: Physical review / A, Vol. 83, No. 6, 062514, 30.06.2011.

Research output: Contribution to journalArticleResearchpeer-review

Beloy, K, Kozlov, MG, Borschevsky, A, Hauser, A, Flambaum, VV & Schwerdtfeger, P 2011, 'Rotational spectrum of the molecular ion NH+ as a probe for α and me/mp variation' Physical review / A, vol. 83, no. 6, 062514. https://doi.org/10.1103/PhysRevA.83.062514
Beloy, K. ; Kozlov, M. G. ; Borschevsky, A. ; Hauser, Andreas ; Flambaum, V. V. ; Schwerdtfeger, P. / Rotational spectrum of the molecular ion NH+ as a probe for α and me/mp variation. In: Physical review / A. 2011 ; Vol. 83, No. 6.
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