Cold collisions ofSr*Srin a magneto-optical trap

Abstract
We present measurements of cold collision processes in an alkaline-earth species. Collisions of 88Sr pairs in a magneto-optic trap are found to be dominated by very-long-range excitation to the nonradiating 1Πg state of Sr2*. We find good agreement between measured loss rate coefficients and a modified form of the semiclassical model that includes retardation effects that allow excitation to metastable molecular states.