Pion correlations and resonance effects in $\bar{p}p$ annihilation to $4\pi^0$ at rest

Abstract. We study $\pi^0\pi^0$ correlations in the exclusive reaction $\bar{p}p\to4\pi^0$ at rest with complete reconstruction of the kinematics for each event. The inclusive distribution is fairly flat 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.