We report a measurement of the branching fraction ratios R(D ( * ) ) ofB → D ( * ) τ −ν τ relative tō B → D ( * ) −ν (where = e or µ) using the full Belle data sample of 772 × 10 6 BB pairs collected at the Υ(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.

With the full data sample of 772 × 10 6 BB pairs recorded by the Belle detector at the KEKB electronpositron collider, the decayB → D Ã τ −ν τ is studied with the hadronic τ decays τ − → π − ν τ and τ − → ρ − ν τ . The τ polarization P τ ðD Ã Þ in two-body hadronic τ decays is measured, as well as the ratio of the branching fractions

We present a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V cb | using the decay B → D ν ( = e, µ) based on 711 fb −1 of e + e − → Υ(4S) data recorded by the Belle detector and containing 772 × 10 6 BB pairs. One B meson in the event is fully reconstructed in a hadronic decay mode while the other, on the signal side, is partially reconstructed from a charged lepton and either a D + or D 0 meson in a total of 23 hadronic decay modes. The isospinaveraged branching fraction of the decay B → D ν is found to be B(B 0 → D − + ν ) = (2.31 ± 0.03(stat) ± 0.11(syst))%. Analyzing the differential decay rate as a function of the hadronic recoil with the parameterization of Caprini, Lellouch and Neubert and using the form-factor prediction G(1) = 1.0541 ± 0.0083 calculated by FNAL/MILC, we obtain ηEW|V cb | = (40.12 ± 1.34) × 10 −3 , where ηEW is the electroweak correction factor. Alternatively, assuming the model-independent form-factor parameterization of Boyd, Grinstein and Lebed and using lattice QCD data from the FNAL/MILC and HPQCD collaborations, we find ηEW|V cb | = (41.10 ± 1.14) × 10 −3 .

We report measurements of the production cross sections of charged pions, kaons, and protons as a function of fractional energy, the event-shape variable called thrust, and the transverse momentum with respect to the thrust axis. These measurements access the transverse momenta created in the fragmentation process, which are of critical importance to the understanding of any transverse-momentum-dependent distribution and fragmentation functions. The low transverse-momentum part of the cross sections can be well described by Gaussians in transverse momentum as is generally assumed but the fractional-energy dependence is nontrivial and different hadron types have varying Gaussian widths. The width of these Gaussians decreases with thrust and shows an initially rising, then decreasing fractional-energy dependence. The widths for pions and kaons are comparable within uncertainties, while those for protons are significantly narrower. These single-hadron cross sections and Gaussian widths are obtained from a 558 fb −1 data sample collected at the ϒð4SÞ resonance with the Belle detector at the KEKB asymmetric-energy e þ e − collider.

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