Abstract
We test whether or not the τ lepton manifests the same couplings as the μ lepton by investigating the relative decay rates in purely leptonic D+ meson decays. We use 281pb-1 of data accumulated at the ψ(3770) resonance with the CLEO-c detector, to limit B(D+→τ+ν)<2.1×10-3 at 90% confidence level (C.L.), thus allowing us to place the first upper limit on the ratio R=Γ(D+→τ+ν)/Γ(D+→μ+ν). 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.
Original language | English (US) |
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Article number | 112005 |
Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |
Volume | 73 |
Issue number | 11 |
DOIs | |
State | Published - 2006 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)