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{0ex{0ex}=0ex{0ex}1, m}₅0ex{0ex}=0ex{0ex}-1 hyperfine state of ^87Rb. 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.