Improved characterization of elastic scattering near a Feshbaeh resonance in 85Rb
We report extensions and corrections to the measurement of the Feshbaeh resonance in 85Rb cold atom collisions reported earlier [J. L. Roberts el al., Phys. Rev. Lett. 81, 5109 (1998)]. In addition to a better determination of the position of the resonance peak 154.9(4) Gl and its width [11.0(4) G], improvements in our techniques now allow the measurement of the absolute size of the classic-scattering rate. This provides a measure of the, s-wave scattering length as a function of magnetic field near the Feshbaeh resonance and constrains the Rb-Rb interaction potential.