  We investigate the atom pair production by superradiant backward-scattering
from a Bose-Einstein condensate. By driving the superradiant process with two
frequencies we can extend both the range of pulse duration and intensity by two
orders of magnitude and obtain full control over the number of scattered atoms
in forward and backward direction. We show that the atoms scattered in forward
direction are strongly correlated with the atoms scattered in backward
direction, which makes resonant superradiant backward-scattering a promising
candidate for many-particle entanglement.
