Constraints on the tau neutrino mass and mixing from precise measurements of tau decay rates
Originally posted at http://arxiv.org/abs/hep-ph/9610242v1. Preprint of an article published in Nuclear Physics B - Proceedings Supplements, 1996.
We have derived constraints on the tau neutrino mass and fourth generation mixing from an analysis of the partial widths of tau lepton decays, in particular: τ¯→e¯ν⁻eντ, τ¯→μ¯ν⁻μντ, τ →π¯ντ, and τ →K¯ντ. We present predictions for the tau decay widths, allowing for a non-zero tau neutrino mass, mντ, and for mixing with a neutrino of mass mνL > MZ/2, which is parametrised using a Cabibbo-like mixing angle, θL. By comparison of these theoretical predictions with the experimental measurements, we obtain the following bounds at the 90% confidence level: mντ < 42 MeV and sin² θL < 0.014.
J. Swain and L. Taylor. "Constraints on the tau neutrino mass and mixing from precise measurements of tau decay rates" 1996
Available at: http://works.bepress.com/jswain/8