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 th e 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 t he three-body recombination rate constants for condensates and cold no ncondensates from number loss in the F = 1,m(f) = -1 hyperfine state o f Rb-87. The ratio of these is 7.4(2.6) which agrees with the theoreti cal factor of 3! and demonstrates that condensate atoms are less bunch ed than noncondensate atoms.