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.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)