Measurement of Vcb using B¯0-->D*+l- ν¯ decays
Abstract
The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element Vcb has been measured using B¯0-->D*+l-ν¯ decays recorded on the Z0 peak using the OPAL detector at LEP. The D*+-->D0π+ decays were reconstructed both in the particular decay modes D0-->K-π+ and D0-->K-π+π0 and via an inclusive technique. The product of Vcb and the decay form factor of the B¯0-->D*+l-ν¯ transition at zero recoil /F(1) was measured to be F(1)Vcb=(37.1+/-1.0+/-2.0)×10- 3, where the uncertainties are statistical and systematic respectively. By using Heavy Quark Effective Theory calculations for /F(1), a value ofVcb=(40.7+/-1.1+/-2.2+/-1.6)×10- 3was obtained, where the third error is due to theoretical uncertainties in the value of /F(1). The branching ratio Br(B¯0-->D*+l-ν¯) was also measured to be /(5.26+/-0.20+/-0.46)%.
- Publication:
-
Physics Letters B
- Pub Date:
- June 2000
- DOI:
- 10.1016/S0370-2693(00)00457-3
- arXiv:
- arXiv:hep-ex/0003013
- Bibcode:
- 2000PhLB..482...15A
- Keywords:
-
- High Energy Physics - Experiment
- E-Print:
- 19 pages, 4 figures, Submitted to Phys. Letts. B