摘要 : We report photoassociative spectroscopy of ~(88)Sr_2 in a magneto-optical trap operating on the ~1S_0 →~3P_1 intercombination line at 689 nm. Photoassociative transitions are driven with a laser red detuned by 600-2400 MHz from th... 展开 We report photoassociative spectroscopy of ~(88)Sr_2 in a magneto-optical trap operating on the ~1S_0 →~3P_1 intercombination line at 689 nm. Photoassociative transitions are driven with a laser red detuned by 600-2400 MHz from the ~1S_0 → ~1P_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 ~1P_1 atomic lifetime (τ = 5.22 ± 0.03 ns) and resolves a discrepancy between experiment and recent theoretical calculations. 收起