Published August 1999 | Version v1
Journal article

Measurement of the Branching Ratio of π0 → e+ e- Using KL → 3π0 Decays in Flight

  • 1. University of Arizona, Tucson, Arizona 85721 (United States)
  • 2. University of California at Los Angeles, Los Angeles, California 90095 (United States)
  • 3. University of California at San Diego, La Jolla, California 92093 (United States)
  • 4. The Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States)
  • 5. University of Colorado, Boulder, Colorado 80309 (United States)
  • 6. Elmhurst College, Elmhurst, Illinois 60126 (United States)
  • 7. Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)
  • 8. Osaka University, Toyonaka, Osaka 560 (Japan)
  • 9. Rice University, Houston, Texas 77005 (United States)
  • 10. Rutgers University, Piscataway, New Jersey 08855 (United States)
  • 11. The Department of Physics and Institute of Nuclear and Particle Physics, University of Virginia, Charlottesville, Virginia 22901 (United States)

Description

The branching ratio of the rare decay π0→e+e- has been measured in E799-II, a rare kaon decay experiment using the KTeV detector at Fermilab. We observed 275 candidate π0→e+e- events, with an expected background of 21.4±6.2 events which includes the contribution from Dalitz decays. We measured B[π0→e+e-, (me+e-/mπ0)2>0.95]=(6.09± 0.40±0.24)x10-8 , where the first error is statistical and the second systematic. This result is the first significant observation of the excess rate for this decay above the unitarity lower bound. copyright 1999 The American Physical Society

Additional details

Publishing Information

Journal Title
Physical Review Letters
Journal Volume
83
Journal Issue
5
Journal Page Range
p. 922-925
ISSN
0031-9007
CODEN
PRLTAO