  We report on the direct imaging of s and d partial-wave interference in cold
collisions of atoms. Two ultracold clouds of Rb87 atoms were accelerated by
magnetic fields to collide at energies near a d-wave shape resonance. The
resulting halos of scattered particles were imaged using laser absorption. By
scanning across the resonance we observed a marked evolution of the scattering
patterns due to the energy dependent phase shifts for the interfering s and d
waves. Since only two partial wave states are involved in the collision process
the scattering yield and angular distributions have a simple interpretation in
terms of a theoretical model.
