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Analysis of Photoassociation Spectra for Giant Helium Dimers

J. Leonard·A. P. Mosk·M. Walhout·P. Van Der Straten·M. Leduc·C. Cohen-Tannoudji
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Abstract

We perform a theoretical analysis to interpret the spectra of purely long-range helium dimers produced by photoassociation (PA) in an ultra-cold gas of metastable helium atoms. The experimental spectrum obtained with the PA laser tuned closed to the $2^3S_1\leftrightarrow 2^3P_0$ atomic line has been reported in a previous Letter. Here, we first focus on the corrections to be applied to the measured resonance frequencies in order to infer the molecular binding energies. We then present a calculation of the vibrational spectra for the purely long-range molecular states, using adiabatic potentials obtained from perturbation theory. With retardation effects taken into account, the agreement between experimental and theoretical determinations of the spectrum for the $0_u^+$ purely long-range potential well is very good. The results yield a determination of the lifetime of the $2^3P$ atomic state.

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J. Leonard, A. P. Mosk, M. Walhout, P. Van Der Straten, M. Leduc, C. Cohen-Tannoudji. 2003-10-01. Analysis of Photoassociation Spectra for Giant Helium Dimers. https://doi.org/10.1103/physreva.69.032702

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