Quantum rainbow scattering at tunable velocities

Elastic scattering cross sections aremeasured for lithium atoms collidingwith rare-gas atoms and SF6 molecules at tunable relative velocities down to similar to 50 m/s. Our scattering apparatus combines a velocity-tunable molecular beam with a magneto-optic trap which provides an ultracold cloud of lithium atoms as a scattering target. Comparison with theory reveals the quantum nature of the collision dynamics in the studied regime, including rainbows as well as orbiting resonances. DOI:10.1103/PhysRevA.86.062711