Semileptonic Results for Summer 2002

All analyses are rescaled to a common set of input parameters defined in common.param. nada

Exclusive Branching Fraction: B0 -> D*lnu

Experiment BF (rescaled) Parameters Remarks
ALEPH 5.91+/- 0.26+/- 0.37 input     parameters Phys.Lett.B395:373-,1997
OPAL 5.30+/- 0.19+/- 0.41 input     parameters Phys.Lett.B482:15-,2000
OPAL 6.07+/- 0.27+/- 0.59 input     parameters Phys.Lett.B482:15-,2000
DELPHI 4.90+/- 0.13+/- 0.35 input     parameters Phys.Lett.B510:55-,2001
BELLE 4.65+/- 0.23+/- 0.40 input     parameters Phys.Lett.B526:247-,2002
CLEO 6.22+/- 0.19+/- 0.39 input     parameters Phys.Rev.Lett.89:081803,2002
DELPHI 5.60+/- 0.20+/- 0.41 input     parameters preliminary
average 5.40 +/- 0.22 (CL = 0.05)    
nada

Exclusive Branching Fraction: B0 -> Dlnu

Experiment BF (rescaled) Parameters Remarks
ALEPH 2.78+/- 0.20+/- 0.46 input     parameters Phys.Lett.B395:373-,1997
CLEO 2.11+/- 0.13+/- 0.16 input     parameters Phys.Rev.Lett.82:3746-,1999
BELLE 2.14+/- 0.12+/- 0.27 input     parameters Phys.Lett.B526:258-268,2002
average 2.17+/- 0.17 (CL = 0.44)    
Note: This is a placeholder (the parameter files for this average are wrong). nada

Inclusive Semileptonic Branching Fraction: B -> Xlnu

Experiment Original Value Rescaled Value Input Remarks
CLEO and ARGUS 10.38+/- 0.08+/- 0.31 10.38+/- 0.08+/- 0.32 input  
BABAR 10.87+/- 0.18+/- 0.3 10.87+/- 0.18+/- 0.35 input  
BELLE 10.90+/- 0.12+/- 0.49 10.90+/- 0.12+/- 0.52 input Error under investigation  
average 10.63+/- 0.19+/- 0.16   parameters Gamma(B->Xclnu) = 0.431 (1+/- 0.019+/- 0.016) 10-10 MeV
LEP HFEW fit 10.63+/- 0.25   parameters Gamma(B->Xclnu) = 0.438 (1+/- 0.024+/- 0.015) 10-10 MeV
Note: The LEP average is not included in the (Upsilon(4S)) average branching fraction. Rather, the two semileptonic widths are combined into the average
Gamma(b->Xc l nu) = 0.434 (1+/- 0.018) 10-10 MeV
This average width is used in the determination of |Vcb| shown below.

Exclusive |Vcb|*F(1)

Experiment |Vcb| F(1) (rescaled) rho2 (rescaled) Parameters Remarks
ALEPH 34.0+/- 2.1+/- 1.6 0.75+/- 0.25+/- 0.37 input     parameters Phys.Lett.B395:373-,1997
OPAL 38.3+/- 1.2+/- 2.5 1.23+/- 0.14+/- 0.39 input     parameters Phys.Lett.B482:15-,2000 (partial reco)
OPAL 38.4+/- 1.6+/- 1.8 1.45+/- 0.21+/- 0.26 input     parameters Phys.Lett.B482:15-,2000 (excl)
DELPHI 36.5+/- 1.4+/- 2.5 1.47+/- 0.14+/- 0.37 input     parameters Phys.Lett.B510:55-,2001
BELLE 36.0+/-1.9+/-1.9 1.45+/- 0.16+/- 0.20 input     parameters Phys.Lett.B526:247-,2002
CLEO 43.4+/- 1.3+/- 1.8 1.61+/- 0.09+/- 0.21 input     parameters Phys.Rev.Lett.89:081803,2002
DELPHI 38.2+/- 1.8+/- 2.0 1.32+/- 0.15+/- 0.32 input     parameters preliminary
average 38.1+/- 1.0 (CL = 0.01) 1.59+/- 0.14(CL = 0.01)   |Vcb| F(1): plot; correlation: plot

With F(1) = 0.91 +/- 0.04, this yields |Vcb| = (41.9 +/-1.1exp +/-1.8theo)10-3 nada

Exclusive |Vcb|*G(1)

Experiment |Vcb| G(1) (rescaled) rho2 (rescaled) Parameters Remarks
ALEPH 39.4+/- 10.0+/- 6.4 0.99+/- 0.98+/- 0.37 input     parameters Phys.Lett.B395:373-,1997
CLEO 44.8+/- 5.8+/- 3.5 1.27+/- 0.25+/- 0.14 input     parameters Phys.Rev.Lett.82:3746-,1999
BELLE 41.2+/- 4.4 +/- 5.1 1.12+/- 0.22+/- 0.14 input     parameters Phys.Lett.B526:258-268,2002
average 41.9+/- 3.7 (CL = 0.99) 1.15+/- 0.16 (CL = 0.99)   plot

With G(1)=1.0+/-0.07 (PDG), this gives |Vcb| = (41.9 +/-3.7exp +/-2.9theo) 10-3 nada

|Vcb| from Inclusive Semileptonic Decays B -> Xlnu

This relies on the published measurements of the photon spectrum and hadronic mass moments (both by CLEO):

Vcb = 40.7 (1 +/-0.010exp +/-0.012lambda_1, Lambda_bar +/-0.0201/m**3,QCD scale ) 10-3

where we use |Vcb| = |Vcb|CLEO SQRT(GammaSL/GammaSL, CLEO), GammaSL, CLEO=0.427