ISSN - 03702693, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2002, vol. 526, p. 247-257
Determination of | vCb| using the semileptonic decay B 0→ D*+e-v-
We present a measurement of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element | Vcb | using a 10.2 fb-1 data sample recorded at the γ(4S) resonance with the Belle detector at the KEKB asymmetric e +e- storage ring. By extrapolating the differential decay width of the Bo → D*+e-v decay to the kinematic limit at which the D*+ is at rest with respect to the B o, we extract the product of | Vcb | with the normalization of the decay form factor F(1), | Vcb | F(1) = (3.54 ± 0.19 ± 0.18) x 10-2, where the first error is statistical and the second is systematic. A value of | Vcb \= (3.88 ±0.21 ±0.20 ±0.19) x 10-2 is obtained using a theoretical calculation of F(1), where the third error is due to the theoretical uncertainty in the value of F(1). The branching fraction B(B0 ->• D*+e-v) is measured to be (4.59 ± 0.23 ± 0.40) x 10-2. © 2002 Elsevier Science B.V. All rights reserved.