Measurement of the B̄0 → D *+ℓ-ν̄ℓ decay rate and |Vcb|

Measurement of the B̄0 → D *+ℓ-ν̄ℓ decay rate and |Vcb|

We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| based on a sample of about 53 700 B̄0 → D*+ℓ-ν̄ℓ decays observed by the BABAR detector. We obtain the branching fraction averaged over ℓ = e, μ, B(B̄0 → D*+ℓ -ν̄ℓ) = (4.90 ± 0.07(stat.) -0.35+0.36(syst.))%. We measure the...

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Bibliographic Details
Main Authors: Aubert, B, Barate, R, Boutigny, D, Couderc, F, Gaillard, J, Hicheur, A, Karyotakis, Y, Lees, J, Tisserand, V, Zghiche, A, Palano, A, Pompili, A, Chen, J, Qi, N, Rong, G, Wang, P, Zhu, Y, Eigen, G, Ofte, I, Stugu, B, Abrams, G, Borgland, A, Breon, AB, Brown, D, Button-Shafer, J
Format: Journal article
Language:English
Published: 2005
Description
Summary:We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| based on a sample of about 53 700 B̄0 → D*+ℓ-ν̄ℓ decays observed by the BABAR detector. We obtain the branching fraction averaged over ℓ = e, μ, B(B̄0 → D*+ℓ -ν̄ℓ) = (4.90 ± 0.07(stat.) -0.35+0.36(syst.))%. We measure the differential decay rate as a function of w, the relativistic boost γ of the D*+ in the B̄0 rest frame. By extrapolating dΓ/dw to the kinematic limit w → 1, we extract the product of |V cb| and the axial form factor A1(w = 1). We combine this measurement with a lattice QCD calculation of A1(w = 1) to determine |Vcb) = (38.7 ± 0.3(stat.) ± 1.7(syst.) -1.3+1.5(theory)) × 10-3. © 2005 The American Physical Society.

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