Updates of Semileptonic Results for End of 2007

This web page contains the results for the End of 2007. The changes of this update with respect to the PDG 2008 update are described here. A new common parameter file is adopted. Moreover, charge coniugated final states are always included.
We thank U. Aglietti, I. Bigi, G. Ferrera, P. Gambino, E. Gardi, P. Giordano, Z. Ligeti, M. Neubert, G. Ricciardi, N. Uraltsev for useful discussions and providing the theoretical codes. We also would like to thank R. Barlow and F. Porter for useful discussions on statistics.
f1vcb_rho2.html

Measurement of |Vcb| F(1) in B0 -> D*lnu

The following average is based on a global four-dimensional fit of |Vcb|F(1), r2, R1 and R2 to the experiments listed. The form-factor parametrization derived by Caprini, Lellouch and Neubert is used (Nucl.Phys. B530 (1998) 153-181 [arXiv:hep-ph/9712417]). This table and the plots are based on the global fit values of R1 and R2. The values reported for each experiment have been rescaled to R1=1.356±0.066 and R2=0.851±0.039 obtained from the fit. The errors contain both the common and the experiment dependent systematic uncertainties. All available experiments have been included in the average.
Experiment |Vcb| F(1) (rescaled) [10-3] r2 (rescaled) Correlation (stat/syst/total) Parameters Remarks
ALEPH (excl) 32.0 +/- 1.8 +/- 1.3 0.49 +/- 0.20 +/- 0.09 0.94/0.60/0.72 input     parameters Phys.Lett.B395:373-,1997
CLEO 41.6 +/- 1.3 +/- 1.8
1.37 +/- 0.09 +/- 0.20
0.87/0.68/0.67
input     parameters
Phys.Rev.Lett.89:081803,2002
OPAL (excl) 37.2 +/- 1.6 +/- 1.5 1.24 +/- 0.20 +/- 0.14 0.95/0.42/0.61 input     parameters Phys.Lett.B482:15-,2000
OPAL (partial reco) 37.6+/- 1.2 +/- 2.4 1.13 +/- 0.13 +/- 0.27 0.77/0.70/0.71 input     parameters Phys.Lett.B482:15-,2000
DELPHI (partial reco) 35.9 +/- 1.4 +/- 2.3 1.18 +/- 0.13 +/- 0.25 0.94/0.77/0.79 input     parameters Phys.Lett.B510:55-,2001
BELLE (excl) 34.9 +/- 2.0 +/- 1.8 1.15 +/- 0.15 +/- 0.10 0.91/0.68/0.78 input     parameters Phys.Lett.B526:247-,2002
DELPHI (excl) 36.6 +/- 1.8 +/- 1.9 1.04 +/-0.14 +/-0.15 0.89/0.50/0.58 input     parameters Eur.Phys.J.C33:213,2004 [hep-ex/0401023]
BABAR (excl) 34.2 +/- 0.3 +/- 1.1 1.18 +/-0.05 +/-0.03 0.27 input     parameters Phys.Rev.D77:032002,2008 [arXiv:0705.4008 [hep-ex]]
Average 36.14 +/- 0.55 1.17 +/- 0.05 0.24
chi2/dof = 33.9/17 (CL = 0.0) eps 1  pdf 1  gif 1  eps 2  pdf 2  gif 2 


nada

Exclusive Branching Fraction: B0 -> D*lnu

This is a list of branching fractions from individual experiments corrected for R1 and R2. The average is based on the integral over the differential rate dG/dw based on the four-dimensional fit of |Vcb|F(1), r2, R1 and R2 (see above). The errors include both the common and experiment dependent systematics. The BaBar tagged result only measures the branching fractions and is averaged independently with the output of the first average.
Experiment BF (rescaled) [%] Remarks
ALEPH (excl) 5.60 +/- 0.26 +/- 0.53 Phys.Lett.B395:373-387,1997 [Spires]
OPAL (excl) 5.22+/- 0.20 +/- 0.5 Exclusive reco, Phys.Lett.B482:15-30,2000 [hep-ex/0003013]
CLEO 6.10 +/- 0.19 +/- 0.4 Phys.Rev.Lett.89:081803,2002
OPAL (partial reco) 5.63 +/- 0.27 +/- 0.65 Partial reco, Phys.Lett.B482:15-30,2000 [hep-ex/0003013]
DELPHI (partial reco) 5.01 +/- 0.15 +/- 0.35 Partial reco, Phys.Lett.B510:55-74,2001 [hep-ex/0104026]
BELLE (excl) 4.80 +/- 0.25 +/- 0.44
Phys.Lett.B526:247-257,2002 [hep-ex/0111060]
DELPHI (excl) 5.60 +/- 0.19 +/- 0.47 Eur.Phys.J.C33:213,2004 [hep-ex/0401023]
BABAR (excl) 4.62 +/- 0.04 +/- 0.33 Phys.Rev.D77:032002,2008 [arXiv:0705.4008 [hep-ex]]
BABAR (tagged) 5.44 +/- 0.16 +/- 0.25 arXiv:0712.3503 [arXiv:0712.3503 [hep-ex]]
Average 5.16 +/- 0.11 chi2/dof = 34.8/9 (CL = 0.) eps pdf gif


nada

Exclusive Branching Fraction: B+ -> D*0lnu

The branching fractions are obtained from the integral over the measured differential decay rates, the average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
CLEO 6.6+/- 0.2+/- 0.4 input     parameters PRD 67, 032001 [arXiv:hep-ex/0210040]
ARGUS 6.5 +/- 1.4+/- 1.1 input     parameters PL B275, 195 [Spires]
BABAR tagged 5.80 +/- 0.15+/- 0.30 input     parameters arXiv:0712.3503 [hep-ex], accepted by PRL [arXiv:0712.3503 [hep-ex]]
Average 6.09 +/- 0.29 chi2/dof = 3.7/2 (CL = 0.17) eps pdf gif
nada

Measurement of |Vcb|G(1) in B0 -> Dlnu

The table and plots give the results of two-dimensional fits to |Vcb|G(1)| and rho2 for different experiments, using the form factor parameterization of Caprini, Lellouch, and Neubert, Nucl.Phys. B530 (1998) 153-181 [arXiv:hep-ph/9712417v1]. nada
Experiment |Vcb| G(1) (rescaled) [10-3] rho2 (rescaled) Correlation (stat/syst/total) Parameters Remarks
ALEPH 38.80+/- 11.80+/- 6.20 0.95+/- 0.98+/- 0.36 0.98/0.99/0.96 input     parameters Phys.Lett.B395:373-387,1997 [Spires]
CLEO 44.80 +/- 5.90+/- 3.45 1.27+/- 0.25+/- 0.14 0.95/0.98/0.96 input     parameters Phys.Rev.Lett.82:3746,1999 [hep-ex/9811042]
BELLE 40.07+/- 4.40 +/- 5.14 1.12+/- 0.22+/- 0.14 0.96/0.96/0.92 input     parameters Phys.Lett.B526:258-268,2002 [hep-ex/0111082]
Average 42.3+/- 4.5 1.17+/- 0.18 0.95/0.94/0.93 chi2/dof = 0.30/4 eps 1  pdf 1  gif 1  eps 2  pdf 2  gif 2 
nada

Exclusive Branching Fraction: B0 -> Dlnu

The branching fractions are obtained from the integral over the measured differential decay rates, the average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
ALEPH 2.25 +/- 0.18+/- 0.36 input     parameters Phys.Lett.B395:373-387,1997 [Spires]
CLEO 2.10+/- 0.13+/- 0.15 input     parameters Phys.Rev.Lett.82:3746,1999 [hep-ex/9811042]
BELLE 2.09+/- 0.12+/- 0.39 input     parameters Phys.Lett.B526:258-268,2002 [hep-ex/0111082]
BABAR 2.22+/- 0.11+/- 0.12 input     parameters arXiv:0712.3503 [hep-ex], accepted by PRL [arXiv:0712.3503 [hep-ex]]
Average 2.17+/- 0.12 chi2/dof = 0.3/3 (CL = 0.96) eps pdf gif
nada

Exclusive Branching Fraction: B+ -> D0lnu

The branching fractions are obtained from the integral over the measured differential decay rates, the average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
CLEO 2.23+/- 0.13+/- 0.17 input     parameters Phys.Rev.Lett.82:3746,1999 [hep-ex/9811042]
CLEO 1.68+/- 0.6+/- 0.21 input     parameters Phys. Rev. D43:651, 1991 [hep-ex/0111082]
BABAR 2.32+/- 0.09+/- 0.09 input     parameters arXiv:0712.3503 [hep-ex], accepted by PRL [arXiv:0712.3503 [hep-ex]]
Average 2.28+/- 0.11 chi2/dof = 0.97/2 (CL = 0.60) eps pdf gif
nada

Exclusive Branching Fraction: B- -> D+ pi- lnu

The branching fractions are obtained from the integral over the measured differential decay rates, the average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
BELLE 0.42+/- 0.04+/- 0.05 input     parameters arXiv:0711.3252 [hep-ex] [arXiv:0711.3252 [hep-ex]]
BABAR 0.42+/- 0.06+/- 0.03 input     parameters arXiv:0712.3503 [hep-ex] [arXiv:0712.3503 [hep-ex]]
Average 0.42+/- 0.05 chi2/dof = 0.001 (CL = 0.98) eps pdf gif
nada

Exclusive Branching Fraction: B- -> D*+ pi- lnu

The branching fractions are obtained from the integral over the measured differential decay rates, the average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
BELLE 0.68+/- 0.08+/- 0.07 input     parameters arXiv:0711.3252 [hep-ex] [arXiv:0711.3252 [hep-ex]]
BABAR 0.59+/- 0.05+/- 0.04 input     parameters arXiv:0712.3503 [hep-ex] [arXiv:0712.3503 [hep-ex]]
Average 0.61+/- 0.05 chi2/dof = 0.5 (CL = 0.49) eps pdf gif
nada

Exclusive Branching Fraction: B0 -> D0 pi+ lnu

The branching fractions are obtained from the integral over the measured differential decay rates, the average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
BELLE 0.43+/- 0.07+/- 0.05 input     parameters arXiv:0711.3252 [hep-ex] [arXiv:0711.3252 [hep-ex]]
BABAR 0.43+/- 0.08+/- 0.03 input     parameters arXiv:0712.3503 [hep-ex] [arXiv:0712.3503 [hep-ex]]
Average 0.43+/- 0.06 chi2/dof = 0.001 (CL = 0.99) eps pdf gif
nada

Exclusive Branching Fraction: B0 -> D*0 pi+ lnu

The branching fractions are obtained from the integral over the measured differential decay rates, the average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
BELLE 0.57+/- 0.21+/- 0.07 input     parameters arXiv:0711.3252 [hep-ex] [arXiv:0711.3252 [hep-ex]]
BABAR 0.48+/- 0.08+/- 0.04 input     parameters arXiv:0712.3503 [hep-ex] [arXiv:0712.3503 [hep-ex]]
Average 0.49+/- 0.08 chi2/dof = 0.15 (CL = 0.70) eps pdf gif

Global Fits (from LP07)


Inclusive Semileptonic (Partial) Branching Fraction for B+/B0 Admixture: B -> Xlnu

This is a one-dimensional fit for the average partial branching fraction for a cut on the momentum
of the lepton at p* > 0.6 GeV/c as measured in the Upsilon(4S) frame.  Note for the Belle (Breco)
measurement, the cut was placed in the rest frame of the B-meson - the difference between the partial branching
above 0.6 GeV/c as measured in either the Upsilon(4S) and B-meson rest frames is entirely negligible.

Experiment BF (Rescaled) [%] Input Remarks
p(l) > 0.6 GeV/c
ARGUS (e tag) 9.15 +/- 0.50 +/- 0.33 input     parameters Phys.Lett.B318:397-404, 1993 [Spires]
BELLE (l tag) 10.30 +/- 0.11 +/- 0.46 input     parameters Phys.Lett.B547:181-192, 2002 [hep-ex/0208033]
CLEO (e tag) 10.23 +/- 0.08 +/- 0.22 input     parameters Phys.Rev.D70:032003,2004 [hep-ex/0403053]
BABAR (e tag) 10.37 +/- 0.06 +/- 0.23 input     parameters Phys.Rev.D69:111104, 2004 [hep-ex/0403030]
BABAR (B_{reco} tag) 10.03 +/- 0.19 +/- 0.33 input     parameters Phys.Rev.D74:091105,2006 [hep-ex/0607111]
BELLE (B_{reco} tag) 10.28 +/- 0.18 +/- 0.24 input     parameters Phys.Rev.D75:032001,2007 [hep-ex/0610012]
Average 10.23 +/- 0.15 chi2/dof = 4.2/5 (CL = 0.52) eps pdf gif
  
Using the results of the global fit (Phys.Rev.D73,073008(2006)) for HQE parameters in the Kinetic Scheme (Eur. Phys. J C 34 (2004) 181), where none of the measurements listed above have been used as input, one can extract the extrapolation factor necessary to calculate the full branching fraction,  fc = 1.0495 +/- 0.0005 +/- 0.0010. The first error is from experiment and theory in the global fit and the second error is assigned as an additional theoretical uncertainty for the ratio GammaSL(0.6)/GammaSL(0.0). For GammaSL this uncertainty is typically 1.5%, on the recommendation of the authors of the fit, for the ratio it is estimated to be 0.1%.
The full branching fraction is extracted as BF( B+/B0 -> X l nu ) = (10.74 +/- 0.16)% .

Inclusive Semileptonic Branching Fraction for B+ -> Xl+nu (from PDG07)

Inclusive Semileptonic Branching Fraction for B0 -> X-l+nu (from PDG07)

Ratio of Semileptonic Branching Fractions for B+ to B0 -> X-l+nu (from PDG07)


Inclusive Vub average for winter 2006

|Vub| from inclusive semileptonic B decays

The results in this section are determined by comparing the measured partial branching fractions in selected regions of phase-space to theoretical calculations of the corresponding rates, which depends on |Vub|. The following theoretical calculations are used to extract |Vub|:

In the |Vub| averages only independent measurements are considered. For the BaBar and Belle B-Reco analyses we had to choose one measurement since the three measurements quoted are strongly correlated. We have chosen the mX analysis.

No attempt is made to average values for |Vub| from the different models, but the results are presented independently per each scheme.

The procedure for performing the average is documented in arXiv:0704.3575.

The input files for the average are linked in the tables with the averages. To summarize briefly, all theoretical uncertainties are considered to be correlated, as are the uncertainties on the modeling of b -> clnu and b -> ulnu decays. Experimental uncertainties (particle identification, reconstruction efficiencies, etc.) are taken as correlated amongst measurements from the same experiment, but not correlated across experiments.

The errors in the tables are experimental (statistical and systematic) and external (theoretical and HQ parameter uncertainties). The average B lifetime used is 1.573 ps. Final state radiation is included in all the measurements.

Note: the input parameters used for the different models are not coming from the same experimental source.

Determination of Vub (BLNP)

Determination of |Vub| (BLNP)

The |Vub| values are obtained using the HQE input parameters mb(SF) and mupi2. Their central values, derived in the kinetic scheme, and using only b -> c l nu moments are taken from Phys.Rev.D73,073008(2006) [arXiv:hep-ph/0507253v3] and LP07 updates.

translated in the SF scheme (M.Neubert) from the kinetic scheme fit using the b->clnu moments . The total error is due to the contribution of the error due to the ellipse (4.707 +0.054/-0.052 GeV) and the one due to scale variation for alphas (4.707 +0.0240/-0.0113 GeV). Similarly, for mupi2 (ellipse error: 0.216 +0.041/-0.043 GeV^2, 'scale' error: 0.216 +0.035/-0.062 GeV^2). BLNP : Vub with HQ parameters from b -> c l nu moments
|Vub | (BLNP)
Experiment Value [10-3] Parameters References Remarks
CLEO (E_{e}) 3.52 +/- 0.41 + 0.38 - 0.32 input Phys.Rev.Lett.88:231803,2002 [arXiv:hep-ex/0202019v1] 2.1 < p < 2.6
BELLE sim. ann. (m_{X}, q^{2}) 3.98 +/- 0.42 + 0.34 - 0.28 input Phys.Rev.Lett.92:101801,2004 [arXiv:hep-ex/0311048v2] mX - Q2, tag with annealing method
BELLE (E_{e}) 4.36 +/- 0.41 + 0.36 - 0.30 input Phys.Lett.B621:28-40 (2005) (arXiv:hep-ex/0504046v2 1.9 < p < 2.6
BABAR (E_{e}) 3.90 +/- 0.22 + 0.35 - 0.30 input Phys.Rev.D73:012006,2006 arXiv:hep-ex/0509040v2 2.0 < p < 2.6
BABAR (E_{e}, s^{max}_{h}) 3.95 +/- 0.27 + 0.42 - 0.36 input Phys.Rev.Lett.95:111801,2005 , Erratum-ibid.97:019903,2006 [arXiv:hep-ex/0506036v3] (Ee-q2)
BELLE (m_{X}) 3.66 +/- 0.24 + 0.29 - 0.24 input Phys.Rev.Lett.95:241801,2005 [arXiv:hep-ex/0505088v2] mX, BRECO tag; other methods (mX-q2 and P+ not used). Cut on the hadronic mass at 1.7 GeV
BABAR (m_{X}) 3.73 +/- 0.18 + 0.33 - 0.28 input [arXiv:0708.3702v1] Accepted by PRL mX, BRECO tag; other methods (mX-q2 and P+ not used). Cut on the hadronic mass at 1.55 GeV
Average +/- exp + theory - theory 3.98 +/- 0.14 + 0.32 - 0.27 chi2/dof = 6.5/6 (CL = 0.37) Plots: eps pdf gif HQE parameter input from b to c l nu moments
The full breakdown of the uncertainties on the average |Vub| above is (all errors quoted in percent):

positive errors: +2.0stat +2.3exp +1.3b2c model +1.4b2u model +7.0HQE param +0.5SF func +0.7sub SF +3.6matching +1.3WA = +8.8tot

negative errors: -2.0stat -2.2exp -1.2b2c model -1.4b2u model -5.8HQE param -0.5SF func -0.7sub SF -3.3matching -1.3WA = -7.7tot

where the fractions correspond to the statistical error (stat), the experimental systematics (exp), the modeling, e.g. branching fractions for exclusive decays, of b -> c l nu and b -> u l nu decays (b2c model and b2u model, respectively), the HQE parameters mb and mupi2 (HQE param), the functional form of the SF (ie the variation from the exponential to the Gaussian form of the SF, SF func), the subleading shape functions (sub SF), the variation of the matching scales (matching), and the Weak Annihilation (WA). No uncertainty is assigned for possible duality violations. The quoted experimental error in the table above corresponds to the statistical, experimental systematic and the b -> c l nu and b -> u l nu modeling errors. The other uncertainties contribute to the theoretical error. Determination of Vub (DGE)

Determination of |Vub| (DGE)

The |Vub| values are obtained using the HQE input parameter (from PDG07):

|Vub| (DGE)
Experiment Value [10-3] Parameters References Remarks
CLEO (E_{e}) 3.85 +/- 0.45 + 0.28 - 0.27 input Phys.Rev.Lett.88:231803,2002 (hep-ex/0202019) 2.1 < p < 2.6
BELLE sim. ann. (m_{X}, q^{2}) 4.43 +/- 0.47 + 0.23 - 0.21 input Phys.Rev.Lett.92:101801,2004 (hep-ex/0311048) mX - Q2, tag with annealing method
BELLE (E_{e}) 4.81 +/- 0.45 + 0.22 - 0.21 input Phys.Lett.B621:28-40 (2005) (hep-ex/0504046) 1.9 < p < 2.6
BABAR (E_{e}) 4.30 +/- 0.29 + 0.25 - 0.24 input Phys.Rev.D73:012006,2006 (hep-ex/0509040) 2.0 < p < 2.6
BABAR (E_{e}, s^{max}_{h}) 4.42 +/- 0.30 + 0.37 - 0.36 input Phys.Rev.Lett.95:241801,2005 (hep-ex/0506036 (version 3, June 2006)) (Ee-q2)
BELLE m_{X} 4.29 +/- 0.28 + 0.27 - 0.24 input Phys.Rev.Lett.95:241801,2005 (hep-ex/0505088) mX, BRECO tag; other methods (mX-q2 and P+ not used)
BABAR m_{X} 4.55 +/- 0.22 + 0.30 - 0.29 input [arXiv:0708.3702v1]. Accepted by PRL mX, BRECO tag; other methods (mX-q2 and P+ not used)
Average +/- exp + theory - theory 4.47 +/- 0.16 + 0.25 - 0.26 chi2/dof = 8.0/6 (CL = 0.24) Plots: eps pdf gif mb input from PDG07 average
The full breakdown of the uncertainties on the average |Vub| above is (all errors quoted in percent):

positive errors: +1.9stat +2.4exp +1.8b2c model +1.1b2u model +0.7alpha_s R_CUT +3.0mb R_CUT +3.0TOTAL SL WIDTH +1.9WA +3.2DGE theory =+6.8tot

negative errors: -1.9stat -2.3exp -1.7b2c model -1.1b2u model -0.8alpha_s R_CUT -3.3mb R_CUT -3.0TOTAL SL WIDTH -1.9WA -3.1DGE theory =-6.9tot

where the fractions correspond to the statistical error (stat), the experimental systematics (exp), the modeling, e.g. branching fractions for exclusive decays, of the b -> c l nu and b -> u l nu decays (b2c model and b2u model, respectively), the effect of the alphas uncertainty on R_CUT (alpha_s R_CUT), the effect of the uncertainty on mb on the prediction of the event fraction (mb R_CUT), the uncertainty on the total semileptonic B width (TOTAL SL WIDTH), the Weak Annihilation (WA) and from the change and variation of scale of the matching scheme (DGE theory). The quoted experimental error in the table above corresponds to the statistical, experimental systematic and the b -> c l and b -> u l nu modeling errors. The other uncertainties contribute to the theoretical error.

Determination of Vub (GGOU)

Determination of |Vub| (GGOU)

We use the input parameters obtained from the fit in the kinetic scheme to the b -> c l nu and b ->s g moments (see above):

The BABAR (E_{e}, s^{max}_{h}) analysis is not included in the average at the moment. The E_{e}, s^{max}_{h} cuts are not yet implemented in the model. Work is under way to include them.

|Vub| (GGOU)
Experiment Value [10-3] Parameters References Remarks
CLEO (E_{e}) 3.70 +/- 0.43 + 0.25 - 0.39 input Phys.Rev.Lett.88:231803,2002 (hep-ex/0202019) 2.1 < p < 2.6
BELLE sim. ann. (m_{X}, q^{2}) 4.15 +/- 0.44 + 0.33 -0.34 input Phys.Rev.Lett.92:101801,2004 (hep-ex/0311048) mX - Q2, tag with annealing method
BELLE (E_{e}) 4.55 +/- 0.42 + 0.22 - 0.31 input Phys.Lett.B621:28-40 (2005) (hep-ex/0504046) 1.9 < p < 2.6
BABAR (E_{e}) 4.07 +/- 0.23 + 0.23 - 0.33 input Phys.Rev.D73:012006,2006 (hep-ex/0509040) 2.0 < p < 2.6
BELLE m_{X} 3.89 +/- 0.26 + 0.19 - 0.22 input Phys.Rev.Lett.95:241801,2005 (hep-ex/0505088) mX, BRECO tag; other methods (mX-q2 and P+ not used)
BABAR m_{X} 4.01 +/- 0.19 + 0.26 - 0.29 input [arXiv:0708.3702v1]. Accepted by PRL. mX, BRECO tag; other methods (mX-q2 and P+ not used)
Average +/- exp + theory - theory 3.94 +/- 0.15 + 0.20 - 0.23 chi2/dof = 5.0/5 (CL = 0.41) Plots: eps pdf gif mb input from PDG07 average
The full breakdown of the uncertainties on the average |Vub| above is (all errors quoted in percent):

positive errors: +2.1stat +2.2exp +1.5b2c model +1.4b2u model +3.9par. +1.8pert. +2.5q2* +0.WA +1.4ff =+6.3tot

negative errors: -2.3stat -2.2exp -1.2b2c model -1.6b2u model -3.8par. -1.7pert. -2.7q2* -3.1WA -0.6ff =-7.0tot

where the fractions correspond to the statistical error (stat), the experimental systematics (exp), the modeling, e.g. branching fractions for exclusive decays, of the b -> c l nu and b -> u l nu decays (b2c model and b2u model, respectively), the value of alpha_s, mb and other non-perturbative parameters (par.), higher order perturbative and non-perturbative corrections (pert.), the modelling of the q2 tail and choice of the scale q2* (q2*), the WA matrix element (WA), the functional form of the distribution functions (ff).

Determination of |Vub| (ADFR)

The |Vub| values are obtained using the HQE input parameter (from PDG07):

|Vub| (AC)
Experiment Value [10-3] Parameters References Remarks
CLEO (E_{e}) 3.47 +/- 0.19 + 0.25 - 0.26 input Phys.Rev.Lett.88:231803,2002 (hep-ex/0202019) 2.3 < p < 2.6, Vub redetermined from partial BF
BELLE sim. ann. (m_{X}, q^{2}) 3.93 +/- 0.38 + 0.25 - 0.26 input Phys.Rev.Lett.92:101801,2004 (hep-ex/0311048) mX - Q2, tag with annealing method
BELLE (E_{e}) 3.18 +/- 0.18 + 0.23 - 0.24 input Phys.Lett.B621:28-40 (2005) (hep-ex/0504046) 2.3 < p < 2.6
BABAR (E_{e}) 3.44 +/- 0.12 + 0.25 - 0.26 input Phys.Rev.D73:012006,2006 (hep-ex/0509040) 2.3 < p < 2.6, Vub redetermined from partial BF
BABAR (E_{e}, s^{max}_{h}) 3.87 +/- 0.27 + 0.25 - 0.26 input Phys.Rev.Lett.95:111801,2005 , Erratum-ibid.97:019903,2006 (hep-ex/0506036 (version 3, June 2006)) (Ee-q2)
BELLE m_{X} 3.91 +/- 0.26 + 0.26 - 0.27 input Phys.Rev.Lett.95:241801,2005 (hep-ex/0505088) mX, BRECO tag; other methods (mX-q2 and P not used)
BABAR m_{X} 4.01 +/- 0.21 + 0.27 - 0.28 input [hep-ex/0507017]. Accepted by PRL mX, BRECO tag; other methods (mX-q2
Average +/- exp + theory - theory 3.78 +/- 0.13 + 0.24 - 0.24 chi2/dof = 8.9/6 (CL = 0.18) Plots: eps pdf gif
The full breakdown of the uncertainties on the average |Vub| above is (all errors quoted in percent):

positive errors: +1.8stat +2.3exp +1.2b2c model +1.3b2u model +2.0alpha_s +1.4Vcb +1.0mb +4.5mc +0.9BF +3.5model =+7.2tot

negative errors: -1.9stat -2.3exp -1.3b2c model -1.4b2u model -2.0alpha_s -1.4Vcb -1.0mb -4.3mc -1.0BF -3.5model =-7.2tot

where the fractions correspond to the statistical error (stat), the experimental systematics (exp), the modeling, e.g. branching fractions for exclusive decays, of the b -> c l nu and b -> u l nu decays (b2c model and b2u model, respectively), the effect of the alphas uncertainty (alpha_s), the effect of the uncertainty on Vcb (Vcb), on the b-quark mass in the MS scheme (mb), on the c-quark mass in the MS scheme (mc), on the semileptonic BF (BF) and on the model (model). The quoted experimental error in the table above corresponds to the statistical, experimental systematic and the b -> c l and b -> u l nu modeling errors. The other uncertainties contribute to the theoretical error.

Determination of Vub (BLL)

Determination of |Vub| (BLL) using the (mx-q2) analyses

The |Vub| values are obtained using the b-quark mass from the 1S Global Fit

|Vub| (BLL) using the (mx-q2) analyses
Experiment Value [10-3] Parameters References Remarks
BELLE breco (m_{X}, q^{2}) 5.01 +/- 0.39 + 0.37 - 0.37 input Phys.Rev.Lett.95:241801,2005 (hep-ex/0505088) mX-q2, BRECO tag
BELLE sim. ann. (m_{X}, q^{2}) 4.71 +/- 0.50 + 0.35 - 0.35 input Phys.Rev.Lett.92:101801,2004 (hep-ex/0311048) mX - Q2, tag with annealing method
BABAR (m_{X}, q^{2}) 4.92 +/- 0.32 + 0.36 - 0.36 input [arXiv:0708.3702v1]. Accepted by PRL. mX-q2, BRECO tag
Average +/- exp +/- theory 4.91 +/- 0.24 + 0.38 - 0.38 chi2/dof = 0.36/2 (CL = 0.83) Plots: eps pdf gif HQE parameter input from b to c l nu and b to s gamma moments
The full breakdown of the uncertainties on the average |Vub| above is (all errors quoted in percent):

positive errors: +3.2stat +3.8exp +1.3b2c model +2.1b2u model +3.0Strf +3.0Pert +4.5Sf +4.0H.O. = +9.0tot

negative errors: -3.2stat -3.8exp -1.3b2c model -2.1b2u model -3.0Strf -3.0Pert -4.5Sf -4.0H.O. = -9.0tot

where the fractions correspond to the statistical error (stat), the experimental systematics (exp), the modeling, e.g. branching fractions for exclusive decays, of b -> c l nu and b -> u l nu decays (b2c model and b2u model, respectively), the residual shape function effects (Strf), the higher order terms in the alphas expansion (Pert), the uncertainty on the b-quark mass (Sf), and the third order terms in the OPE expansion(H.O.). No uncertainty is assigned for possible duality violations. Vub comparison_with LLR method

Shape Function Model Independent extraction of |Vub| from inclusive decays and comparison of results

Several years ago, M. Neubert (Phys. Rev. D49, 4623 (1994) ) suggested that |Vub| could be extracted by combining weighted integrals over the photon spectrum in B->Xs gamma decays with integrals over the lepton momentum spectrum near the kinematic endpoint in inclusive B->Xulnu decays decays. The underlying assumption is that the QCD interactions affecting these two processes are the same to leading order, and therefore ratios of decay rates for the two processes have significantly lower sensitivity to the choice of the shape-functions parameterization.
So far, there are two BABAR measurements based on this suggestion to extract |Vub| from charmless B-meson decays from inclusive distributions for different regions of phase space.
BABAR measured |Vub| in inclusive decays using the prescription of Leibovich, Low, and Rothstein (LLR), Phys.Rev.D62:014010,2000 [arXiv:hep-ph/0001028v2], and Phys.Lett.B486:86-91,2000 [arXiv:hep-ph/0005124v1], that extracts |Vub| with reduced model dependence by combining data of the hadronic mass spectrum from B->Xulnu decays with that of the photon energy spectrum from B->Xs gamma decays (Phys.Rev. D72 (2005) 052004 [arXiv:hep-ex/0508004v2]).
Using BABAR measurements of the lepton momentum spectrum near the kinematic endpoint, Phys.Rev. D73 (2006) 012006 [arXiv:hep-ex/0509040v2], two different theoretical prescriptions were tried to extract |Vub|, Phys.Rev.D76:114003,2007 [arXiv:hep-ph/0702072], namely LLR (Phys.Rev. D61 (2000) 053006 [arXiv:hep-ph/9909404v2]]) and LNP, a calculation by Lange, Neubert and Paz (JHEP 0510 (2005) 084 [arXiv:hep-ph/0508178v2] and JHEP 0601 (2006) 104 [arXiv:hep-ph/0511098v1]). In the following, we provide a comparison of the results of the different |Vub| extractions.

The errors on |Vub| are experimental and theoretical, respectively, for the first three results and experimental on B->Xulnu, experimental on B->Xsgamma, theoretical and due to |Vts| for the last two measurments.

Vub comparison_with LLR method
Description Vub [10-3] Reference
HFAG Ave. (BLNP) 3.98 +/- 0.14 + 0.32 - 0.27
HFAG Ave. (DGE) 4.47 +/- 0.16 + 0.25 - 0.26
HFAG Ave. (GGOU) 3.94 +/- 0.15 + 0.20 - 0.23
HFAG Ave. (ADFR) 3.78 +/- 0.13 + 0.24 - 0.24
HFAG Ave. (BLL) 4.91 +/- 0.24 + 0.38 - 0.38
BABAR (LLR) 4.43 +/- 0.45 +/- 0.29 Phys.Rev.Lett. 96 (2006) 221801 [arXiv:hep-ex/0601046v2]
BABAR endpoint (LLR) 4.28 +/- 0.29 +/- 0.29 +/- 0.26 +/- 0.28 Phys.Rev.D76:114003,2007 [arXiv:hep-ph/0702072]
BABAR endpoint (LNP) 4.40 +/- 0.30 +/- 0.41 +/- 0.23 Phys.Rev.D76:114003,2007 [arXiv:hep-ph/0702072]

A plot of this table is available in three formats: eps pdf gif


B -> pi l nu average

Branching fractions of B0 -> pi- l+ nu

The measurements quoted here include both B0 and B+ decays; the average assumes equality of the semileptonic decays widths for these isospin-conjugate states, and is quoted for B0 decays.

Experiment / Mode BF [10-4] BF(q2<16 GeV2) [10-4] BF(q2>16 GeV2) [10-4] Reference
BABAR SL tag: B ^{+} \rightarrow \pi^{0} l^{+} \nu \times 2\tau_{0}/\tau_{+} 1.37 +/- 0.34 +/- 0.15 1.18 +/- 0.30 +/- 0.12 0.19 +/- 0.23 +/- 0.08 SL tag, Phys.Rev.Lett.97:211801,2006 [hep-ex/0607089] (input)(param)
BABAR B_{reco} tag: B ^{+} \rightarrow \pi^{0} l^{+} \nu \times 2\tau_{0}/\tau_{+} 1.54 +/- 0.41 +/- 0.21 1.05 +/- 0.36 +/- 0.15 0.49 +/- 0.23 +/- 0.11 Breco tag, Phys.Rev.Lett.97:211801,2006 [hep-ex/0607089] (input)(param)
BELLE SL tag: B ^{+} \rightarrow \pi^{0} l^{+} \nu \times 2\tau_{0}/\tau_{+} 1.45 +/- 0.26 +/- 0.15 1.07 +/- 0.23 +/- 0.11 0.38 +/- 0.15 +/- 0.04 SL tag, Phys.Lett.B648:139-148,2007 [hep-ex/0604024] (input)(param)
BELLE B_{reco} tag: B ^{+} \rightarrow \pi^{0} l^{+} \nu \times 2\tau_{0}/\tau_{+} 1.62 +/- 0.32 +/- 0.11 NA NA Preliminary, Breco tag hep-ex/0610054 (input)
BABAR SL tag: B ^{0} \rightarrow \pi^{-} l^{+} \nu 1.12 +/- 0.25 +/- 0.10 0.83 +/- 0.22 +/- 0.08 0.29 +/- 0.15 +/- 0.04 SL tag, Phys.Rev.Lett.97:211801,2006 [hep-ex/0607089] (input)(param)
BELLE SL tag: B ^{0} \rightarrow \pi^{-} l^{+} \nu 1.38 +/- 0.19 +/- 0.14 1.02 +/- 0.16 +/- 0.11 0.36 +/- 0.10 +/- 0.04 SL tag, Phys.Lett.B648:139-148,2007 [hep-ex/0604024] (input)(param)
BABAR B_{reco} tag: B ^{0} \rightarrow \pi^{-} l^{+} \nu 1.07 +/- 0.27 +/- 0.15 0.42 +/- 0.18 +/- 0.05 0.65 +/- 0.20 +/- 0.13 Breco tag, Phys.Rev.Lett.97:211801,2006 [hep-ex/0607089] (input)(param)
CLEO untagged: B \rightarrow \pi l^{+} \nu 1.37 +/- 0.15 +/- 0.11 0.96 +/- 0.13 +/- 0.10 0.41 +/- 0.08 +/- 0.04 Untagged, Phys.Rev.Lett.99:041802,2007 [arXiv:hep-ex/0703041v2] (input)(param)
BABAR untagged: B \rightarrow \pi l^{+} \nu 1.46 +/- 0.07 +/- 0.08 0.96 +/- 0.13 +/- 0.10 0.38 +/- 0.04 +/- 0.03 Untagged loose neutrino, Phys. Rev. Lett. 98, 091801 (2007) [hep-ex/0612020 ] (input)(param)
BELLE B_{reco} tag: B ^{0} \rightarrow \pi^{-} l^{+} \nu 1.49 +/- 0.26 +/- 0.06 NA NA Preliminary, Breco tag hep-ex/0610054 (input)
Average: B ^{0} \rightarrow \pi^{-} l^{+} \nu 1.40 +/- 0.06 +/- 0.06 0.95 +/- 0.05 +/- 0.05 0.38 +/- 0.03 +/- 0.03 Plots: epspdfgif   chi2/dof = 3.0/9 (CL = 0.97)

Vub from B -> pi l nu average
FF calculation Vub [10-3] q2 range FF norm (ps-1) Reference
Ball-Zwicky q^2 < 16 3.38 +/- 0.13 +0.56-0.37 <16 GeV2 5.44 +/- 1.43 Phys. Rev. D71:014015 (2005) [hep-ph/0406232]
HPQCD q^2 > 16 3.47 +/- 0.20 +0.60-0.39 >16 GeV2 2.07 +/- 0.57 Phys.Rev.D73, 074502 (2006), Erratum-ibid.D75:119906,2007 [hep-lat/0601021]
FNAL q^2 > 16 3.69 +/- 0.21 +0.64-0.42 >16 GeV2 1.83 +/- 0.50 Nucl.Phys.Proc.Suppl.140:461-463,2005 [hep-lat/0409116]
APE q^2 > 16 3.72 +/- 0.21 +1.43-0.66 >16 GeV2 1.80 +/- 0.86 Nucl. Phys. B 619 (2000) 565-587 [hep-lat/0011065]

A plot of this table is available in three formats: eps pdf gif

FF calculation Vub [10-3] q2 range FF norm (ps-1) Reference
Ball-Zwicky full q^2 3.41 +/- 0.11 +0.67-0.42 full 7.74 +/- 2.32 Phys. Rev. D71:014015 (2005) [hep-ph/0406232]
HPQCD full q^2 3.11 +/- 0.10 +0.73-0.43 full 9.10 +/- 3.13 Phys.Rev.D73, 074502 (2006), Erratum-ibid.D75:119906,2007 [hep-lat/0601021]
FNAL full q^2 3.80 +/- 0.12 +0.88-0.52 full 6.24 +/- 2.12 Nucl.Phys.Proc.Suppl.140:461-463,2005 [hep-lat/0409116]
APE full q^2 3.59 +/- 0.11 +1.11-0.57 full 7.0 +/- 2.9 Nucl. Phys. B 619 (2000) 565-587 [hep-lat/0011065]

A plot of this table is available in three formats: eps pdf gif

Branching fractions of B->rholnu

Branching fractions of B0 -> rho- l+ nu

The measurements quoted here include both B0 and B+ decays; the average assumes equality of the semileptonic decays widths for these isospin-conjugate states, and is quoted for B0 decays.

Experiment/Mode BF [10-4] Reference
CLEO: B^{0} \rightarrow \rho^{-} l^{+} \nu 2.69 +/-0.41 +/- 0.63 Phys. Rev. D 61, 052001 (2000) [hep-ex/9905056] (input)
CLEO: B^{0} \rightarrow \rho^{-} l^{+} \nu 2.93 +/-0.37 +/- 0.37 PRL 99, 041802 (2007)[arXiv:hep-ex/0703041v2] (input)
BABAR: B^{0} \rightarrow \rho^{-} l^{+} \nu 2.14 +/-0.21 +/-0.55 Untagged, Phys .Rev. D72, 051102 (2005) [hep-ex/0507003] (input)
Average: B ^{0} \rightarrow \rho^{-} l^{+} \nu 2.64 +/- 0.21 +/- 0.33 Plots: eps pdf gif   chi2/dof = 1.1/2 (CL = 0.58)
nada

Branching fractions of other exclusive charmless semileptonic decays

Experiment Mode BF [10-4] Reference
CLEO B+-> eta l+ nu 0.84 +/-0.31 +0.16 +/-0.09 Phys. Rev. D 68, 072003 (2003) [hep-ex/0304019]
BABAR B+-> eta l+ nu 0.84 +/-0.27 +/- 0.21 Preliminary Breco [hep-ex/0607066]
BABAR B+-> eta' l+ nu 0.33 +/-0.60 +/- 0.30 Preliminary Breco [hep-ex/0607066]
BELLE B+-> omega l+ nu 1.3 +/-0.4 +/-0.2 +/-0.3 Phys. Rev. Lett. 93:131803 (2004)[hep-ex/0402023]


Last update: 2010/Jan/15 Concezio Bozzi fix typo in LLR results for inclusive Vub.
Previous update: 2008/May/05 Francesca Di Lodovico (Bug fix).