Determination of lifetimes of 6PJ levels and ground-state polarizability of Cs from the van der Waals coefficient C6 -: art. no. 053403

A method for determination of atomic lifetimes from the value of dispersion coefficient C-6 of molecular potentials correlating to two ground-state atoms is proposed. The method is illustrated with atomic Cs using C-6 deduced from high-resolution Feshbach spectroscopy. The following lifetimes are determined: tau(6P1/2)=34.80+/-0.07 ns and tau(6P3/2)=30.39+/-0.06 ns. The underlying electric-dipole matrix elements are required for a refined analysis of parity violation in Cs-133. We also obtain static polarizability of the Cs ground state, alpha(0)=400.49(81) atomic units. It is demonstrated that the uncertainties may be considerably reduced as the coefficient C-6 is constrained further.