Km. Jones et al., MEASUREMENT OF THE ATOMIC NA(3P) LIFETIME AND OF RETARDATION IN THE INTERACTION BETWEEN 2 ATOMS BOUND IN A MOLECULE, Europhysics letters, 35(2), 1996, pp. 85-90
From molecular spectroscopy of the Na-2 purely long range O-g(-), stat
e we determine the Na(3P) lifetime and measure the predicted but previ
ously unobserved effect of retardation in the interaction between two
atoms. Our lifetime tau(P-3/2) = 16.230(16) ns helps to remove a longs
tanding discrepancy between experiment and theory. Electron cloud over
lap is unimportant in the 0(g)(-) state (R > 55 alpha(0)) and the spec
trum is calculated, ab initio, from atomic properties. By measuring th
e binding energies the 120 MHz correction due to retardation of the re
sonant-dipole R(-3) interaction is confirmed.