Coherence, correlations, and collisions: What one learns about Bose-Einstein condensates from their decay

We have used three-body recombination rates as a sensitive probe of the statistical correlations between atoms in Bose-Einstein condensates (BEC) and in ultracold noncondensed dilute atomic gases. We infer that density fluctuations are suppressed in the BEC samples. We measured the three-body recombination rate constants for condensates and cold noncondensates from number loss in the F = 1,m(f) = -1 hyperfine state of Rb-87. The ratio of these is 7.4(2.6) which agrees with the theoretical factor of 3! and demonstrates that condensate atoms are less bunched than noncondensate atoms.