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arXiv · hep-ex/0604043

An Investigation of D+--> tau+ nu

P. Rubin·CLEO Collaboration
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Abstract

We test whether or not the tau lepton manifests the same couplings as the mu lepton by investigating the relative decay rates in purely leptonic D+ meson decays. Specifically, we place the first upper limit on the ratio R=Gamma(D+ -> tau+ nu)/Gamma(D+ -> mu+ nu). We use 281 inverse pb of data accumulated at the psi(3770) resonance with the CLEO-c detector, to determine B(D+ -> tau+ nu) < 2.1 x 10^(-3) at 90% confidence level (C. L.). The ratio of R to the Standard Model expectation of 2.65 then is <1.8 at 90% C. L., consistent with the prediction of lepton universality.

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P. Rubin, CLEO Collaboration. 2006-04-21. An Investigation of D+--> tau+ nu. https://doi.org/10.1103/physrevd.73.112005

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