Nagel, SB, Mickelson PG, Saenz AD, Martinez YN, Chen YC, Killian TC, Pellegrini P, Cote R.
2005.
Photoassociative spectroscopy at long range in ultracold strontium, Mar 4. Physical Review Letters. 94
AbstractWe report photoassociative spectroscopy of Sr-88(2) in a magneto-optical trap operating on the S-1(0)-->P-3(1) intercombination line at 689 nm. Photoassociative transitions are driven with a laser red detuned by 600-2400 MHz from the S-1(0)-->P-1(1) atomic resonance at 461 nm. Photoassociation takes place at extremely large internuclear separation, and the photoassociative spectrum is strongly affected by relativistic retardation. A fit of the transition frequencies determines the P-1(1) atomic lifetime (tau=5.22+/-0.03 ns) and resolves a discrepancy between experiment and recent theoretical calculations.
] 