ISSN - 03702693, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2002, vol. 526, p. 258-268
Measurement of B(Bo - D+Í- v) and determination of | vCb |
We present a measurement of the branching fraction for the semileptonic B decay B o → D+ℓ-v, where ℓ-can be either an electron or a muon. We find Γ( o → D+ℓ-v) = (13.79 ± 0.76 ± 2.51) ns-1, and the resulting branching fraction B( 0→ D+ℓ-v) = (2.13 ± 0.12 ± 0.39)%, where the first error is statistical and the second systematic. We also investigate the Bo → D+ℓ-v form factor and the implications of the result for |VCb|. From a fit to the differential decay distribution we obtain the rate normalization |V Cb| FD(1) = (4.11 ± 0.44 ± 0.52) x 10 -2. Using a theoretical calculation of FD(1), the Cabibbo-Kobayashi-Maskawa matrix element | Vcb| = (4.19 ± 0.45 ± 0.53 ± 0.30) x 10-2 is obtained, where the last error comes from the theoretical uncertainty of FD(1). The results are based on a data sample of 10.2 fb-1 recorded at the γ(4S) resonance with the Belle detector at the KEKB e+e- collider. © 2002 Elsevier Science B.V. All rights reserved.