Spectroscopic determination of the s-wave scattering lengths of 86Sr and   88Sr
  We report the use of photoassociative spectroscopy to determine the ground state s-wave scattering lengths for the main bosonic isotopes of strontium, 86Sr and 88Sr. Photoassociative transitions are driven with a laser red-detuned by up to 1400 GHz from the 1S0-1P1 atomic resonance at 461 nm. A minimum in the transition amplitude for 86Sr at -494+/-5 GHz allows us to determine the scattering lengths 610a0 < a86 < 2300a0 for 86Sr and a much smaller value of -1a0 < a88 < 13a0 for 88Sr. 
P.G. Mickelson, Y.N. Martinez, A.D. Saenz, S.B. Nagel, Y.C. Chen, T.C.   Killian, P. Pellegrini, and R. Cote