ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2010, vol. 82, p. -
Measurement of the form factors of the decay B0→D⊃* -ℓ+νℓ and determination of the CKM matrix element |Vcb|
This article describes a determination of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| from the decay B0→D⊃* -ℓ+νℓ using 711fb-1 of Belle data collected near the Υ(4S) resonance. We simultaneously measure the product of the form factor normalization F(1) and the matrix element |V cb| as well as the three parameters ρ2, R1(1) and R2(1), which determine the form factors of this decay in the framework of the heavy quark effective theory. The results, based on about 120000 reconstructed B0→D⊃* -ℓ+νℓ decays, are ρ2=1.214±0.034±0.009, R1(1)=1.401±0. 034±0.018, R2(1)=0.864±0.024±0.008 and F(1)|Vcb|=(34.6±0.2±1.0)×10-3. The branching fraction of B0→D⊃* -ℓ+νℓ is measured at the same time; we obtain a value of B(B0→D⊃* -ℓ+νℓ)=(4.58±0.03±0. 26)%. The errors correspond to the statistical and systematic uncertainties. These results give the most precise determination of the form factor parameters and F(1)|Vcb| to date. In addition, a direct, model-independent determination of the form factor shapes has been carried out. © 2010 The American Physical Society.