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arXiv · hep-ex/9806035

An upper limit for the tau-neutrino mass from tau --> 5 pi+- nu_tau decays

The OPAL Collaboration·K. Ackerstaff et al
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Abstract

An upper limit for the tau-neutrino mass has been determined from the decay tau -> 5pi+- ν_tau using data collected with the OPAL detector from 1991 to 1995 in e+e- collisions at \sqrt{s} ~ M_Z. A limit of 43.2 MeV at 95% CL is obtained using a two-dimensional method in the 5pi invariant mass and energy distribution from 22 selected events. Combining this result with OPAL's previously published measurement using tau+tau- -> 3h+- \bar{nu}_tau 3h-+ ν_tau decays, a new combined limit of m_{nu_tau} < 27.6 MeV (95% CL) is obtained.

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The OPAL Collaboration, K. Ackerstaff et al. 1998-06-27. An upper limit for the tau-neutrino mass from tau --> 5 pi+- nu_tau decays. https://doi.org/10.1007/s100520050264

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