Abouzaid E, Arenton M, Barker AR, Bellantoni L, Blucher E, Bock GJ, Cheu E, Coleman R, Corcoran MD, Cox B, Erwin AR, Escobar CO, Glazov A, Golossanov A, Gomes RA, Gouffon P, Hsiung YB, Jensen DA, Kessler R, Kotera K, Ledovskoy A, McBride PL, Monnier E, Nguyen H, Niclasen R, Phillips DG, Ramberg EJ, Ray RE, Ronquest M, Santos E, Slater W, Smith D, Solomey N, Swallow EC, Toale PA, Tschirhart R, Wah YW, Wang J, White HB, Whitmore J, Wilking MJ, Winstein B, Winston R, Worcester ET, Yamanaka T, Zimmerman ED, Zukanovich RF. Determination of the parity of the neutral pion via its four-electron decay.
PHYSICAL REVIEW LETTERS 2008;
100:182001. [PMID:
18518364 DOI:
10.1103/physrevlett.100.182001]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Indexed: 05/26/2023]
Abstract
We present a new determination of the parity of the neutral pion via the double Dalitz decay pi0-->e+e-e+e-. Our sample, which consists of 30,511 candidate decays, was collected from KL-->pi0pi0pi0 decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative pi0 parity and place a limit on scalar contributions to the pi0-->e+e-e+e- decay amplitude of less than 3.3% assuming CPT conservation. The pi0gamma*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(pi0-->e+e-e+e-)=(3.26+/-0.18)x10(-5).
Collapse