Measurement of |Vcb| using B0 -> D*+l-v decays                                 
  
The magnitude of the CKM matrix element Vcb is measured                        
using B --> D* l nu decays recorded on the Z0 peak                             
using the OPAL detector at LEP. The D* --> D0 pi+ decays                       
were reconstructed both in the particular decay modes D0 --> K-pi+             
and D0 --> K-pi+pi0 and via an inclusive technique. The product of |Vcb|       
and the decay form factor of the B --> D* l nu transition at zero recoil F(1)  
was measured to be F(1)|Vcb| =(37.1 +/- 1.0 (stat.) +/- 2.0 (syst.)) x 10^-3.  
By using HQET calculations for F(1), we obtain                                 
Vcb =(37.1 +/- 1.0 (stat.) +/- 2.0 (syst.) +/- 2.0 (theory)) x 10^-3.          
  
 Parallel session :7                   
 Plenary  session :3