We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element jV cb j from B 0 → D Ã− l þ ν l decays, reconstructed with the full Belle data set of 711 fb −1 integrated luminosity. Two form factor parametrizations, originally conceived by the Caprini-Lellouch-Neubert (CLN) and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product F ð1Þη EW jV cb j and the decay form factors, where F ð1Þ is the normalization factor and η EW is a small electroweak correction. In the CLN parametrization we find F ð1Þη EW jV cb j ¼ ð35.06 AE 0.15 AE 0.56Þ × 10 −3 , ρ 2 ¼ 1.106 AE 0.031 AE 0.007, R 1 ð1Þ ¼ 1.229 AE 0.028 AE 0.009, R 2 ð1Þ ¼ 0.852 AE 0.021 AE 0.006. For the BGL parametrization we obtain F ð1Þη EW jV cb j ¼ ð34.93 AE 0.23 AE 0.59Þ × 10 −3 , which is consistent with the world average when correcting for F ð1Þη EW . The branching fraction of B 0 → D Ã− l þ ν l is measured to be BðB 0 → D Ã− l þ ν l Þ ¼ ð4.90 AE 0.02 AE 0.16Þ%. We also present a new test of lepton flavor universality violation in semileptonic B decays, BðB 0 →D Ã− e þ νÞ BðB 0 →D Ã− μ þ νÞ ¼ 1.01 AE 0.01 AE 0.03. The errors quoted correspond to the statistical and systematic uncertainties, respectively. This is the most precise measurement of F ð1Þη EW jV cb j and form factors to date and the first experimental study of the BGL form factor parametrization in an experimental measurement.

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We report preliminary results on the analysis of the three-body Υ( 10860) → B Bπ, Υ(10860) → [B B * + c.c.]π and Υ(10860) → B * B * π decays including an observation of the Υ(10860) → Z ± b (10610)π ∓ → [B B * + c.c.] ± π ∓ and Υ(10860) → Z ± b (10650)π ∓ → [B * B * ] ± π ∓ decays as intermediate channels. We measure branching fractions of the three-body decays to be B(Υ(10860) → [B B * + c.c.] ± π ∓ ) = (28.3 ± 2.9 ± 4.6) × 10 −3 and B(Υ(10860) → [B * B * ] ± π ∓ ) = (14.1 ± 1.9 ± 2.4) × 10 −3 and set 90% C.L. upper limit B(Υ(10860) → [B B] ± π ∓ ) < 4.0 × 10 −3 . We also report results on the amplitude analysis of the three-body Υ(10860) → Υ(nS)π + π − , n = 1, 2, 3 decays and the analysis of the internal structure of the three-body Υ(10860) → h b (mP )π + π − , m = 1, 2 decays. The results are based on a 121.4 fb −1 data sample collected with the Belle detector at a center-of-mass energy near the Υ(10860).

We present measurements of the branching fractions for the decays B → Kμ+μ− and B → Ke+e−, and their ratio (RK), using a data sample of 711 fb−1 that contains 772 × 106$$ B\overline{B} $$ B B ¯ events. The data were collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The ratio RK is measured in five bins of dilepton invariant-mass-squared (q2): q2 ∈ (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2/c4, along with the whole q2 region. The RK value for q2 ∈ (1.0, 6.0) GeV2/c4 is $$ {1.03}_{-0.24}^{+0.28} $$ 1.03 − 0.24 + 0.28 ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for RK are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q2 bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q2 ∈ (1.0, 6.0) GeV2/c4 bin in the mode with muon final states. The measured differential branching fractions, $$ d\mathrm{\mathcal{B}} $$ d ℬ /dq2, are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kμ±e∓ decays and set 90% confidence-level upper limits on the branching fraction in the range of 10−8 for B+ → K+μ±e∓, and B0 → K0μ±e∓ modes.

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