Determination of the Cs2 0g-(P3/2) potential curve and of Cs6P1/2,3/2 atomic radiative lifetimes from photoassociation spectroscopy -: art. no. 052506

An analytical expression for the external well of the Cs-2 0(g)(-)(6s+6P(3/2)) double-well potential curve is derived, involving asymptotic parameters fitted on the spectrum obtained from photoassociation of ultracold cesium atoms and ultracold molecule formation [Fioretti , Europhys. J. D 5, 389 (1999)]. The results are compared to a previous Rydberg-Klein-Rees determination from our group, and may have consequences on the determination of cesium triplet scattering length. Values for radiative lifetimes tau(3/2)=30.462(3) ns and tau(1/2)=34.88(2) ns of the 6P(3/2) and 6P(1/2) atomic levels, respectively, are extracted with an accuracy better than previous determinations. The method of Derevianko and Porsev [Phys. Rev. A 65, 053403 (2002)], allows the derivation of an improved value for the van der Waals coefficient of ground-state cesium molecule, C-6(6s)=6828(19) a.u.