Improved measurement of the K+ → π+ νν̄ branching ratio

V. V. Anisimovsky, A. V. Artamonov, B. Bassalleck, B. Bhuyan, E. W. Blackmore, D. A. Bryman, S. Chen, I. H. Chiang, I. A. Christidi, P. S. Cooper, M. V. Diwan, J. S. Frank, T. Fujiwara, J. Hu, A. P. Ivashkin, D. E. Jaffe, S. Kabe, S. H. Kettell, M. M. Khabibullin, A. N. KhotjantsevP. Kitching, M. Kobayashi, T. K. Komatsubara, A. Konaka, A. P. Kozhevnikov, Yu G. Kudenko, A. Kushnirenko, L. G. Landsberg, B. Lewis, K. K. Li, L. S. Littenberg, J. A. Macdonald, J. Mildenberger, O. V. Mineev, M. Miyajima, K. Mizouchi, V. A. Mukhin, N. Muramatsu, T. Nakano, M. Nomachi, T. Nomura, T. Numao, V. F. Obraztsov, K. Omata, D. I. Patalakha, S. V. Petrenko, R. Poutissou, E. J. Ramberg, G. Redlinger, T. Sato, T. Sekiguchi, T. Shinkawa, R. C. Strand, S. Sugimoto, Y. Tamagawa, R. Tschirhart, T. Tsunemi, D. V. Vavilov, B. Viren, N. V. Yershov, Y. Yoshimura, T. Yoshioka

Research output: Contribution to journalArticlepeer-review

156 Citations (Scopus)


The upper kinematic limit for K+→π +νν̄ was observed by experiment E949 at Brookhaven National Laboratory. The new procedure enabled to estimates of the expected background and signal rates inside and outside the signal region. Examination of the signal region for the data set yielded one event with P=227.3±2.7 MeV/c, R=39.2±1.2 cm and E=128.9±3.6 MeV. It was suggested that at the measured central value of the branching ratio, the additional event had a signal to background ratio of 0.9.

Original languageEnglish
Article number031801
Pages (from-to)031801-1-031801-4
JournalPhysical review letters
Issue number3
Publication statusPublished - Jul 16 2004
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)


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