  Collisions and chemical reactions of molecules in Bose-Einstein condensates
(BECs) are extremely sensitive to weak fields. This sensitivity arises due to
the high density of compound resonances and a macroscopic number of molecules
with kinetic energy E=0 (perfect energy resolution). We suggest that chemical
reactions in molecular BECs could be used to enhance effects produced by small
external perturbations and search for a parity-violating energy difference in
chiral molecules.
