RADIATIVE LIFETIME OF THE 2P STATE OF LITHIUM

We determine the radial dipole moment between the 2S and 2P states of atomic lithium by analyzing the long-range vibrational eigenenergies o f the singly excited diatomic molecule. The result can be expressed in terms of the 2P(1/2) radiative lifetime of Li-7, which is found to be 27.102(2)(7) ns. This result agrees with most current atomic-structur e calculations and resolves the long-standing disagreement with previo us experiment. The current level of precision is sensitive to relativi stic effects in the atomic-structure calculation and to non-Born-Oppen heimer and radiation retardation effects in the molecule.