ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2007, vol. 99, p. -
Observation of B0→D*-τ+ντ decay at belle
We report an observation of the decay B0→D*-τ+ντ in a data sample containing 535×106 BB̄ pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find a signal with a significance of 5.2σ and measure the branching fraction B(B0→D*-τ+ντ)=(2.02-0.37+0.40(stat)±0.37(syst))%. This is the first observation of an exclusive B decay with a b→cτντ transition. © 2007 The American Physical Society.