ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2010, vol. 82, p. -
Observation of B+→D̄*0τ+ντ and evidence for B+→D̄0τ+ντ at Belle
We present measurements of B+→D̄ *0τ+ντ and B+→D̄0τ+ντ decays in a data sample of 657×106 BB̄ pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find 446-56+58 B+→D̄*0τ+ντ events with a significance of 8.1 standard deviations, and 146-41+42 B+→D̄0τ+ν τ events with a significance of 3.5 standard deviations. The latter signal provides the first evidence for this decay mode. The measured branching fractions are B(B+→D̄*0τ+ντ)=(2. 12-0.27+0.28(stat)±0.29(syst))% and B(B+→D̄0τ+ν τ)=(0.77±0.22(stat)±0.12(syst))%. © 2010 The American Physical Society.