Measurement of the branching ratio of 0e+e- from 0s produced by KL000 decays in flight

K. S. McFarland, R. A. Briere, Elliott C Cheu, D. A. Harris, G. Makoff, A. Roodman, B. Schwingenheuer, S. V. Somalwar, Y. W. Wah, B. Winstein, R. Winston, K. Arisaka, D. Roberts, W. Slater, M. Weaver, A. R. Barker, E. C. Swallow, G. J. Bock, R. Coleman, M. CrislerJ. Enagonio, R. Ford, Y. B. Hsiung, D. A. Jensen, E. Ramberg, R. Tschirhart, E. M. Collins, G. D. Gollin, T. Nakaya, T. Yamanaka, P. Gu, P. Haas, W. P. Hogan, S. K. Kim, J. N. Matthews, S. S. Myung, S. Schnetzer, G. B. Thomson, Y. Zou

Research output: Contribution to journalArticle

15 Scopus citations


The Fermilab E799 Collaboration has carried out a search for the rare decay 0e+e- using 0s produced from KL'000 decays in flight. We observe a signal of nine events with an e+e- mass close to the 0 mass where only one event is predicted from other known processes. From this, we measure B(0e+e-,(mee/m0)20. 95) =[7.6-2.8+3.9(stat)0.5(syst)]×10-8, over and above the contribution from 0 Dalitz decays. Correcting for radiative effects, we find this result consistent with theoretical expectations from standard-model processes.

Original languageEnglish (US)
Pages (from-to)31-34
Number of pages4
JournalPhysical Review Letters
Issue number1
Publication statusPublished - 1993
Externally publishedYes


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

McFarland, K. S., Briere, R. A., Cheu, E. C., Harris, D. A., Makoff, G., Roodman, A., ... Zou, Y. (1993). Measurement of the branching ratio of 0e+e- from 0s produced by KL000 decays in flight. Physical Review Letters, 71(1), 31-34.