Determination of the Parity of the Neutral Pion Via the Four-Electron Decay

Download or read book Determination of the Parity of the Neutral Pion Via the Four-Electron Decay written by and published by . This book was released on 2008 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a new determination of the parity of the neutral pion via the double Dalitz decay [pi]° 2!ee−ee−. Our sample, which consists of 30 511 candidate decays, was collected from K{sub L} 2![pi]°[pi]°[pi]° decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative [pi]° parity, and place a limit on scalar contributions to the [pi]° 2!e+e−e+e− decay amplitude of less than 3.3% assuming CPT conservation. The [pi]°[gamma]*[gamma]* 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([pi]° 2!e+e−e+e−) = (3.26 ± 0.18) x 10−5.