  Interactions between particles can be strongly altered by their environment.
We demonstrate a technique for modifying interactions between ultracold atoms
by dressing the bare atomic states with light, creating an effective
interaction of vastly increased range that scatters states of finite relative
angular momentum at collision energies where only s-wave scattering would
normally be expected. We collided two optically dressed neutral atomic
Bose-Einstein condensates with equal, and opposite, momenta and observed that
the usual s-wave distribution of scattered atoms was altered by the appearance
of d- and g-wave contributions. This technique is expected to enable quantum
simulation of exotic systems, including those predicted to support Majorana
fermions.
