Key points are not available for this paper at this time.
From molecular spectroscopy of the Na2 purely long-range 0−g state we determine the Na(3P) lifetime and measure the predicted but previously unobserved effect of retardation in the interaction between two atoms. Our lifetime τ(P3/2) = 16.230(16) ns helps to remove a longstanding discrepancy between experiment and theory. Electron cloud overlap is unimportant in the 0−g state (R > 55a0) and the spectrum is calculated, ab initio, from atomic properties. By measuring the binding energies the 120 MHz correction due to retardation of the resonant-dipole R−3 interaction is confirmed.
Jones et al. (Wed,) studied this question.