Measurement of the branching ratio of [pi][sup 0][r arrow][ital e][sup +][ital e[minus]] from [pi][sup 0]'s produced by [ital K][sub [ital L]][r arrow][pi][sup 0][pi][sup 0][pi][sup 0] decays in flight

Journal Article · Mon Jul 05 04:00:00 EDT 1993 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.71.31· OSTI ID:7369085

McFarland, K S; Briere, R A; Cheu, E; Harris, D A; Makoff, G; Roodman, A; Schwingenheuer, B; Somalwar, S V; Wah, Y W; Winstein, B; Winston, R ^[1]; Arisaka, K; Roberts, D; Slater, W; Weaver, M ^[2]; Barker, A R ^[3]; Swallow, E C ^[4]; Bock, G J; Coleman, R; Crisler, M ; Enagonio, J; Ford, R; Hsiung, Y B; Jensen, D A; Ramberg, E; Tschirhart, R ^[5]; Collins, E M; Gollin, G D ^[6]; Nakaya, T; Yamanaka, T ^[7]

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1. The Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States)
2. University of California at Los Angeles, Los Angeles, California 90024 (United States)
3. University of Colorado, Boulder, Colorado 80309 (United States)
4. Elmhurst College, Elmhurst, Illinois 60126 (United States) The Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States)
5. Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)
6. University of Illinois, Urbana, Illinois 61801 (United States)
7. Department of Physics, Osaka Univ

The Fermilab E799 Collaboration has carried out a search for the rare decay [pi][sup 0][r arrow][ital e][sup +][ital e[minus]] using [pi][sup 0]'s produced from [ital K][sub [ital L]][r arrow][pi][sup 0][pi][sup 0][pi][sup 0] decays in flight. We observe a signal of nine events with an [ital e][sup +][ital e[minus]] mass close to the [pi][sup 0] mass where only one event is predicted from other known processes. From this, we measure [ital B]([pi][sup 0][r arrow][ital e][sup +][ital e[minus]],([ital m][sub [ital e][ital e]]/[ital m][sub [pi]][sup 0])[sup 2][gt]0.95) =[7.6[sub [minus]2.8][sup +3.9](stat)[plus minus]0.5(syst)][times]10[sup [minus]8], over and above the contribution from [pi][sup 0] Dalitz decays. Correcting for radiative effects, we find this result consistent with theoretical expectations from standard-model processes.

• OSTI ID: 7369085
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 71:1; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

662350* -- Decays of Mesons-- (1992-)
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662420 -- Properties of Mesons & Meson Resonances-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATORS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BOSONS
BRANCHING RATIO
CYCLIC ACCELERATORS
DECAY
ELECTROMAGNETIC PARTICLE DECAY
ELECTRONS
ELEMENTARY PARTICLES
FERMILAB TEVATRON
FERMIONS
HADRONS
KAONS
KAONS NEUTRAL
KAONS NEUTRAL LONG-LIVED
LEPTONS
MATHEMATICAL MODELS
MATTER
MESONS
PARTICLE DECAY
PARTICLE MODELS
PIONS
PIONS NEUTRAL
POSITRONS
PSEUDOSCALAR MESONS
STANDARD MODEL
STRANGE MESONS
STRANGE PARTICLES
SYNCHROTRONS
UNIFIED GAUGE MODELS
UNITARITY