We present a new determination of the parity of the neutral pion via the double Dalitz decay π0→e+e-e+e-. Our sample, which consists of 30511 candidate decays, was collected from KL→π0π0π0 decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative π0 parity and place a limit on scalar contributions to the π0→e+e-e+e- decay amplitude of less than 3.3% assuming CPT conservation. The π0γ*γ* form factor is well described by a momentum-dependent model with a slope parameter fit to the final state phase-space distribution. Additionally, we have measured the branching ratio of this mode to be B(π0→e+e-e+e-)=(3.26±0.18)×10-5.
ASJC Scopus subject areas
- Physics and Astronomy(all)