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Search for the Lepton-Flavor-Violating Decay $τ^- \to μ^- η$ at Belle

Y. Enari
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Abstract

We have searched for the Lepton Flavor Violating decay $τ^- \to μ^- η$ using a data sample of 84.3 fb$^{-1}$ accumulated with the Belle detector at KEK. The $η$-meson was detected through the decay modes: $η\to γγ$ and $π^+π^-π^0$. No signal candidates are found, and we obtain an upper limit for the branching fraction ${\cal B}(τ^- \to μ^- η)<3.4\times 10^{-7}$ at the 90% confidence level.

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Y. Enari. 2004-04-21. Search for the Lepton-Flavor-Violating Decay $τ^- \to μ^- η$ at Belle. https://doi.org/10.1103/physrevlett.93.081803

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