Pion correlations and resonance effects in {pp} annihilation at rest to 2π +2π ^-π ^0
Abstract
We study π π correlations in the exclusive reaction {pp} -> 2π +2π ^-π ^0 at rest with complete reconstruction of the kinematics for each event. Inclusive and differential distributions properly normalized show an enhancement for small invariant masses M++, M-- of like-pion pairs. An even stronger enhancement is seen for the double differential distributions for low pion-pair masses. The signal is strongest when the π 0 energy is large and much weaker when this energy is small. Dynamical models with resonances in the final state are confronted with the data. For the kinematic situation where the π channel is important the simulation predicts a large pion correlation for the double differential density, qualitatively explaining the observed bahaviour. The stochastic HBT mechanism is not supported by these findings for the exclusive annihilation reaction studied.
- Publication:
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European Physical Journal C
- Pub Date:
- January 1999
- Bibcode:
- 1999EPJC....6..437C