Molecules in a Bose-Einstein condensate

State-selected rubidium-87 molecules were created at rest in a dilute Bose- Einstein condensate of rubidium-87 atoms with coherent free-bound stimulate d Raman transitions. The transition rate exhibited a resonance Line shape w ith an extremely narrow width as small as 1.5 kilohertz. The precise shape and position of the resonance are sensitive to the mean-field interactions between the molecules and the atomic condensate. As a result, we were able to measure the molecule-condensate interactions. This method allows molecul ar binding energies to be determined with unprecedented accuracy and is of interest as a mechanism for the generation of a molecular Bose-Einstein con densate.