Upper bound on the τ-neutrino mass from the previously unobserved decay mode τ→KKπντ

G. B. Mills, T. Pal, W. B. Atwood, P. H. Baillon, B. C. Barish, G. R. Bonneaud, A. Courau, G. J. Donaldson, R. Dubois, M. M. Duro, E. E. Elsen, S. G. Gao, Y. Z. Huang, G. M. Irwin, R. P. Johnson, H. Kichimi, J. Kirkby, D. E. Klem, D. E. Koop, J. LudwigA. Ogawa, D. Perret-Gallix, R. Pitthan, D. L. Pollard, C. Y. Prescott, L. Z. Rivkin, L. S. Rochester, W. Ruckstuhl, M. Sakuda, S. S. Sherman, E. J. Siskind, R. Stroynowski, S. Q. Wang, S. G. Wojcicki, H. Yamamoto, W. G. Yan, C. C. Young

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36 Citations (Scopus)


We report a measurement of the branching ratios for two decay modes of the τ lepton: RB(τ±→K±Kπ±ντ)=(0.22-0. 11+0.17)% and RB(τ±→K±ππ±(π0)ντ)= (0.22-0.13+0.16)%. The separation of these channels is accomplished in the DELCO detector by use of a gas erenkov counter to identify fast kaons. The invariant-mass distribution of the K±Kπ± system has been used to set an upper bound on the τ neutrino mass of 157 MeV at 95% confidence limit.

Original languageEnglish
Pages (from-to)624-627
Number of pages4
JournalPhysical review letters
Issue number7
Publication statusPublished - 1985
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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