Hot topics from Belle experiment

We present the first evidence of the decay B → τ−ν̄τ , using 414 fb −1 of data collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. Events are tagged by fully reconstructing one of the B mesons in hadronic modes. We detect the signal with a significance of 4.0 standard deviations including systematics, and measure the branching fraction to be B(B− → τ−ν̄τ ) = (1.06 +0.34 −0.28(stat) +0.22 −0.25(syst))×10 −4 . We also report results based on 1.86fb data collected by the Belle detector at the Υ(5S) resonance. Several exclusive Bs decays Bs → D (∗)+ s π −(ρ−) and Bs → J/ψφ(η) are studied. The Bs meson production is found to proceed predominantly through the creation of B∗ s B̄ ∗ s pairs. Upper limits on Bs → K +K−, Bs → φγ, Bs → γγ and Bs → D (∗)+ s D (∗)− s decays are also reported.