Measurement of the branching ratio of B¯→ D(∗)τ- ν¯τ relative to B¯→ D(∗)lν¯l decays with hadronic tagging at Belle

The LHCb Collaboration

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We report a measurement of the branching fraction ratios R(D(∗)) of B¯→D(∗)τ-ν¯τ relative to B¯→D(∗) -ν¯ (where =e or μ) using the full Belle data sample of 772×106BB¯ pairs collected at the (4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured values are R(D)=0.375±0.064(stat)±0.026(syst) and R(D∗)=0.293±0.038(stat)±0.015(syst). The analysis uses hadronic reconstruction of the tag-side B meson and purely leptonic τ decays. The results are consistent with earlier measurements and do not show a significant deviation from the standard model prediction.
Original languageEnglish
Article number072014
Number of pages14
JournalPhysical Review D
Issue number7
Publication statusPublished - 2015
Externally publishedYes

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