  We study pi0pi0 correlations in the exclusive reaction ppbar -> 4pi0 at rest
with complete reconstruction of the kinematics for each event. The inclusive
distribution shows a dip at small invariant mass of the pion pair while a small
enhancement in the double differential distribution is observed for small
invariant masses of both pion pairs. Dynamical models with resonances in the
final state are shown to be consistent with the data while the stochastic HBT
mechanism is not supported by the present findings.
