We study the photodissociation chemistry of a quantum degenerate gas of
bosonic triatomic ABC molecules, assuming two open rearrangement channels
(AB+C or A+BC). The equations of motion are equivalent to those of a
parametric multimode laser, resulting in an exponential buildup of macroscopic
mode populations. By exponentially amplifying a small differential in the
single-particle rate-coefficients, Bose stimulation leads to a nearly complete
selectivity of the collective N-body process, indicating a novel type of
ultra-selective quantum degenerate chemistry.Comment: 5 pages, 3 figure