Detailed Spectroscopy of the Cs2 a3Sigma+u State and Implications for Measurements Sensitive to Variation of the Electron/Proton Mass Ratio

Published

August 21, 2012

Author(s)

S Sainis, J. M. Sage, D DeMille, Eite Tiesinga, Svetlana Kotochigova

Abstract

We present spectroscopic data on moderately bound levels in the Cs2 a3Sigma+ u state. The data have sufficient resolution to be sensitive to rotational and second-order spin-orbit splittings as well as hyperfine and vibrational structure. Quantum numbers are assigned to the levels via selection rules and a global fit to other available data for the a3Sigma + u and coupled X1Sigma+ g states. The analysis focuses in particular on nearly degenerate pairs of a and X state levels, energy differences between which can be highly sensitive to possible variations in the electron-to-proton mass ratio (cf. DeMille et al., Phys. Rev. Lett. 100, 043202 (2008)). We also characterize the electric (E1) and magnetic (M1) dipole transition strengths between nearly degenerate a and X ro-vibrational levels and find that both types of transitions are feasible with current technology and could give complementary information.

Citation

Physical Review A

Volume

86

Pub Type

Journals

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Keywords

ultracold atoms, cesium, molecular spectroscopy, fundamental constants

Citation

Sainis, S. , Sage, J. , DeMille, D. , Tiesinga, E. and Kotochigova, S. (2012), Detailed Spectroscopy of the Cs2 a3Sigma+u State and Implications for Measurements Sensitive to Variation of the Electron/Proton Mass Ratio, Physical Review A, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=911503 (Accessed October 9, 2025)