Updates of Semileptonic Results for ICHEP08 2008

This web page contains the results for ICHEP 2008. The changes of this update with respect to the the End of Year 2007 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.
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. 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=1.369±0.064 and R2=0.846±0.038 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) 31.6 +/- 1.8 +/- 1.3 0.50 +/- 0.20 +/- 0.09 0.94/0.54/0.76 input     parameters Phys.Lett.B395:373-,1997
CLEO 41.3 +/- 1.3 +/- 1.8
1.37 +/- 0.08 +/- 0.18
0.91/0.85/0.84
input     parameters
Phys.Rev.Lett.89:081803,2002
OPAL (excl) 36.9 +/- 1.6 +/- 1.5 1.24 +/- 0.20 +/- 0.14 0.95/0.44/0.69 input     parameters Phys.Lett.B482:15-,2000
OPAL (partial reco) 37.6+/- 1.2 +/- 2.4 1.14 +/- 0.13 +/- 0.27 0.77/0.73/0.74 input     parameters Phys.Lett.B482:15-,2000
DELPHI (partial reco) 35.8 +/- 1.4 +/- 2.3 1.18 +/- 0.13 +/- 0.25 0.94/0.63/0.67 input     parameters Phys.Lett.B510:55-,2001
BELLE (excl) 34.7 +/- 0.2 +/- 1. 1.159 +/- 0.040 +/- 0.026 0.91/0.87/0.88 input     parameters Phys.Lett.B526:247-,2002
DELPHI (excl) 36.3 +/- 1.8 +/- 1.9 1.04 +/-0.14 +/-0.15 0.89/0.76/0.82 input     parameters Eur.Phys.J.C33:213,2004
BABAR (excl) 33.9 +/- 0.3 +/- 1.1 1.18 +/-0.05 +/-0.03 0.27/0.09/0.12 input     parameters Phys.Rev.D77:032002,2008 [arXiv:0705.4008 [hep-ex]]
BABAR (D*0) 34.9 +/- 0.8 +/- 1.4 1.11 +/-0.06 +/- 0.08 0.90/0.07/0.29 input     parameters Phys.Rev.Lett. 100, 231803, 2008 [arXiv:0712.3493 [hep-ex]]
BABAR (Global Fit) 35.7 +/- 0.2 +/- 1.2 1.20 +/-0.02 +/- 0.07 0.38/0.74/0.73 input     parameters Phys.Rev.D79:012002, 2009 [arXiv:0809.0828 [hep-ex]]
Average 35.41 +/- 0.52 1.16 +/- 0.05 0.20
chi2/dof = 39./21 (CL = 0.01%) eps 1  pdf 1  gif 1  eps 2  pdf 2  gif 2  eps 2 (zoom)  pdf 2 (zoom)  gif 2 (zoom) 


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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) 5.44 +/- 0.25 +/- 0.20 Phys.Lett.B395:373-387,1997 [Spires]
OPAL (excl) 5.17+/- 0.20 +/- 0.38 Exclusive reco, Phys.Lett.B482:15-30,2000 [hep-ex/0003013]
CLEO 6.02 +/- 0.19 +/- 0.20 Phys.Rev.Lett.89:081803,2002
OPAL (partial reco) 5.63 +/- 0.27 +/- 0.43 Partial reco, Phys.Lett.B482:15-30,2000 [hep-ex/0003013]
DELPHI (partial reco) 5.00 +/- 0.15 +/- 0.18 Partial reco,Phys.Lett.B510:55-74,2001 [hep-ex/0104026]
BELLE (excl) 4.75 +/- 0.25 +/- 0.19
Phys.Lett.B526:247-257,2002 [hep-ex/0111060]
DELPHI (excl) 5.53 +/- 0.19 +/- 0.34 Eur.Phys.J.C33:213,2004 [hep-ex/0401023]
BABAR (excl) 4.53 +/- 0.04 +/- 0.13 Phys.Rev.D77:032002,2008 [arXiv:0705.4008 [hep-ex]]
BABAR (tagged) 5.40 +/- 0.16 +/- 0.25 Phys.Rev.Lett.100:151802, 2008 [arXiv:0712.3503 [hep-ex]]
Average 5.05 +/- 0.10 chi2/dof = 35.8/9 (CL = 0.00005) eps pdf gif


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Exclusive Branching Fraction: B- -> D1(D*-pi-)lnu

We report the average for the product of branching fractions of B- -> D1(D*-pi)lnu and D1 -> D*+pi-. Apart for the CLEO,BELLE and BABAR results, the other measurements are for the final state D1(D*-pi-)X. We assume that no particle is left in the X system.
Experiment BF (rescaled) [%] Parameters Remarks
ALEPH 0.45+/- 0.10+/- 0.07 input     parameters Z.Phys. C 73:601,1997 [Z.Phys.C73]
OPAL 0.59 +/- 0.21+/- 0.10 input     parameters Eur.Phys. J.C 30:467,2003 [hep-ex/0301018]
CLEO 0.35 +/- 0.08+/- 0.06 input     parameters Phys.Rev.Lett.80:4127,1998 [hep-ex/9708035]
D0 0.22 +/- 0.02+/- 0.04 input     parameters Phys.Rev.Lett.95:171803,1995 [hep-ex/0507046]
BELLE 0.44 +/- 0.07+/- 0.06 input     parameters Phys.Rev.D77:091503, 2008 [arXiv:0711.3252 [hep-ex]]
BABAR Tagged 0.28 +/- 0.03+/- 0.03 input     parameters Phys.Rev.Lett.101:261802,2008 [arXiv:0808.0528 [hep-ex]]
BABAR Untagged 0.29 +/- 0.02+/- 0.02 input     parameters [arXiv:0808.0333 [hep-ex]]
Average 0.28 +/- 0.02 chi2/dof = 13.2/6 (CL = 0.04) eps pdf gif
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Exclusive Branching Fraction: B- -> D2(D*-pi-)lnu

We report the average for the product of branching fractions of B- -> D2(D*-pi)lnu and D2 -> D*+pi-. Apart for the CLEO, BELLE and BABAR results, the other measurements are for the final state D2(D*-pi-)X. We assume that no particle is left in the X system.
Experiment BF (rescaled) [%] Parameters Remarks
CLEO 0.06 +/- 0.07+/- 0.01 input     parameters Phys.Rev.Lett.80:4127,1998 [hep-ex/9708035]
D0 0.09 +/- 0.02+/- 0.02 input     parameters Phys.Rev.Lett.95:171803,1995 [hep-ex/0507046]
BELLE 0.19 +/- 0.06+/- 0.03 input     parameters Phys.Rev.D77:091503, 2008 [arXiv:0711.3252 [hep-ex]]
BABAR Tagged 0.067 +/- 0.009 +/- 0.016 input     parameters Phys.Rev.Lett.101:261802,2008 [arXiv:0808.0528 [hep-ex]]
BABAR Untagged 0.089 +/- 0.013+/- 0.008 input     parameters [arXiv:0808.0333 [hep-ex]]
Average 0.082 +/- 0.011 chi2/dof = 3.9/4 (CL = 0.42) 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 BaBar tagged result is obtained by a 1-d fit to the missing mass in fully reconstructed events. 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 Phys.Rev.Lett.82:3746,1999 [hep-ex/9811042]
ARGUS 6.1 +/- 1.4+/- 1.0 input     parameters Phys.Lett.B395:373-387,1997 [Spires]
BABAR Tagged 5.71 +/- 0.15+/- 0.30 input     parameters Phys.Rev.Lett.100:151802, 2008 [arXiv:0712.3503 [hep-ex]]
BABAR Untagged 5.31 +/- 0.08+/- 0.40 input     parameters Phys.Rev.Lett. 100, 231803 (2008) [arXiv:0712.3493 [hep-ex]]
BABAR Global Fit 5.37 +/- 0.02+/- 0.21 input     parameters Phys.Rev.D79:012002, 2009 [arXiv:0809.0828 [hep-ex]]
Average 5.66 +/- 0.18 chi2/dof = 9.3/5 (CL = 0.05) eps pdf gif
nada

Measurement of |Vcb|G(1) in B -> 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 38.08+/- 11.80+/- 6.09 0.91+/- 0.98+/- 0.36 0.98/0.99/0.96 input     parameters Phys.Lett.B395:373-387,1997 [Spires]
CLEO 44.53 +/- 5.90+/- 3.42 1.27+/- 0.25+/- 0.14 0.95/0.98/0.96 input     parameters Phys.Rev.Lett.82:3746,1999 [hep-ex/9811042]
BELLE 40.70+/- 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]
BABAR Global Fit 43.8 +/- 0.8 +/- 2.1 1.22+/- 0.04 +/- 0.06 0.63/0.63/0.63 input     parameters Phys.Rev.D79:012002, 2009 [arXiv:0809.0828 [hep-ex]]
BABAR Tagged 42.3 +/- 1.90 +/- 1.0 1.20+/- 0.09+/- 0.04 0.95/0.4/0.7 input     parameters [arXiv:0807.4978 [hep-ex]]
Average 42.4+/- 0.7 +/- 1.4 1.19+/- 0.04 +/- 0.04 0.96/0.91/0.88 chi2/dof = 1.2/8 (CL = 0.997) eps 1  pdf 1  gif 1  eps 2  pdf 2  gif 2 ; eps 2 (zoom)  pdf 2 (zoom)  gif 2 (zoom) 
nada

Exclusive Branching Fraction: B0 -> D-lnu

The branching fractions are obtained from the integral over the measured differential decay rates. The BaBar result is obtained by a 1-d fit to the missing mass in fully reconstructed events. 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 2.20+/- 0.11+/- 0.12 input     parameters Phys.Rev.Lett.100:151802, 2008 [arXiv:0712.3503 [hep-ex]]
Average 2.16+/- 0.12 chi2/dof = 0.2/3 (CL = 0.97) eps pdf gif
nada

Exclusive Branching Fraction: B- -> D0lnu

The branching fractions are obtained from the integral over the measured differential decay rates. The BaBar result is obtained by a 1-d fit to the missing mass in fully reconstructed events. The average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
CLEO-2 2.20 +/- 0.13+/- 0.17 input     parameters Phys.Rev.Lett.82:3746,1999 [hep-ex/9811042]
CLEO 1.66+/- 0.6+/- 0.21 input     parameters Phys. Rev. D43:651, 1991 [hep-ex/0111082]
BABAR 2.27+/- 0.09+/- 0.09 input     parameters Phys.Rev.Lett.100:151802, 2008 [arXiv:0712.3503 [hep-ex]]
Average 2.23+/- 0.11 chi2/dof = 0.95/2 (CL = 0.62) eps pdf gif
nada

Exclusive Branching Fraction: B- -> D0lnu using both isospin conjugate states

The branching fractions are obtained from the integral over the measured differential decay rates. The BaBar tagged result is obtained by a 1-d fit to the missing mass in fully reconstructed events. The average BF is obtained from a one-dimensional fit of the measurements listed.
Experiment BF (rescaled) [%] Parameters Remarks
BaBar Global Fit 2.36+/- 0.03+/- 0.12 input     parameters Phys.Rev.D79:012002, 2009 [arXiv:0809.0828 [hep-ex]]
BaBar Tagged 2.30+/- 0.06+/- 0.08 input     parameters [arXiv:0807.4978 [hep-ex]]
Average 2.32+/- 0.09 chi2/dof = 0.25/1 (CL = 0.62) eps pdf gif
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Exclusive Branching Fraction: B- -> D+ pi- lnu

The branching fractions are obtained by a 1-d fit to the missing mass in fully reconstructed events.
Experiment BF (rescaled) [%] Parameters Remarks
BELLE 0.42+/- 0.04+/- 0.05 input     parameters [Phys.Rev.D77:091503, 2008 [arXiv:0711.3252 [hep-ex]]
BABAR 0.42+/- 0.06+/- 0.03 input     parameters [Phys.Rev.Lett.100:151802, 2008 [arXiv:0712.3503 [hep-ex]]
Average 0.42+/- 0.05 chi2/dof = 0.002 (CL = 0.97) eps pdf gif
nada

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

The branching fractions are obtained by a 1-d fit to the missing mass in fully reconstructed events.
Experiment BF (rescaled) [%] Parameters Remarks
BELLE 0.68+/- 0.08+/- 0.07 input     parameters Phys.Rev.D77:091503, 2008 [arXiv:0711.3252 [hep-ex]]
BABAR 0.59+/- 0.05+/- 0.04 input     parameters Phys.Rev.Lett.100:151802, 2008 [arXiv:0712.3503 [hep-ex]]
Average 0.61+/- 0.05 chi2/dof = 0.5 (CL = 0.47) eps pdf gif
nada

Exclusive Branching Fraction: B0 -> D0 pi+ lnu

The branching fractions are obtained by a 1-d fit to the missing mass in fully reconstructed events.
Experiment BF (rescaled) [%] Parameters Remarks
BELLE 0.43+/- 0.07+/- 0.05 input     parameters Phys.Rev.D77:091503, 2008 [arXiv:0711.3252 [hep-ex]]
BABAR 0.42+/- 0.08+/- 0.03 input     parameters Phys.Rev.Lett.100:151802, 2008 [arXiv:0712.3503 [hep-ex]]
Average 0.43+/- 0.06 chi2/dof = 0.002 (CL = 0.96) eps pdf gif
nada

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

The branching fractions are obtained by a 1-d fit to the missing mass in fully reconstructed events.
Experiment BF (rescaled) [%] Parameters Remarks
BELLE 0.57+/- 0.21+/- 0.07 input     parameters Phys.Rev.D77:091503, 2008 [arXiv:0711.3252 [hep-ex]]
BABAR 0.48+/- 0.08+/- 0.04 input     parameters Phys.Rev.Lett.100:151802, 2008 [arXiv:0712.3503 [hep-ex]]
Average 0.49+/- 0.08 chi2/dof = 0.15 (CL = 0.70) eps pdf gif

Inclusive |Vcb| from global fits

Inclusive |Vcb| from global fits

Global fits to the moments of inclusive distributions in B -> Xc l nu (lepton energy and hadron mass) and B -> Xs gamma (photon energy) transitions are performed in the framework of the Heavy Quark Expansion (HQE), using the calculations in the kinetic mass scheme:

Fits to the B -> Xc l nu & B -> Xs gamma moments and separately to the B -> Xc l nu moments only are performed.

Global fit in the kinetic scheme
Moments |Vcb| (10-3) mb (GeV) mc (GeV) mupi2 (GeV2)
B -> Xc l nu & B -> Xs gamma 41.67 +/- 0.43 +/- 0.08 +/- 0.58 4.601 +/- 0.034 1.165 +/- 0.050 0.440 +/- 0.040
B -> Xc l nu 41.48 +/- 0.47 +/- 0.08 +/- 0.58 4.659 +/- 0.049 1.285 +/- 0.078 0.428 +/- 0.044
Reference: web page
Plots: (|Vcb|, mb): eps, pdf (mupi2, mb): eps, pdf

The errors quoted are the results of the MINUIT fit, where the covariance matrix includes experimental and estimated theoretical uncertainties. On |Vcb| there are additional uncertainties: The second error corresponds to the uncertainty in the B lifetime, and the third error is an additional theoretical uncertainty of 1.4% related to the conversion of the semileptonic branching ratio into |Vcb|. The b quark mass and mupi2 also also translated in other schemes as necessary input parameters for the extraction of |Vub| from inclusive b->ulnu decays.

Translation to other schemes of the parameters from the B -> Xc l nu & B -> Xs gamma fit
Scheme mb (GeV) mupi2 (GeV2) Comments
SF 4.631 +0.041 -0.035 GeV 0.272 +0.056 -0.076 GeV Using code from M. Neubert. The total error, for both parameters, is due to the contribution of the error due to the ellipse and the one due to scale variation for alphas.
MSbar 4.243 +- 0.042 GeV E. Gardi
1S 4.70 +/- 0.03 GeV


Inclusive Vub average for ICHEP08

|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 measurements for which the correlation is known are considered. They are either independent measurements or correlated measurements for which the correlation among the analyses is available (eg the BaBar B-Reco analyses). If the analyses are correlated but the correlation is not known, the analysis with the smallest error is considered.

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

The procedure for performing the average is documented in [arXiv:0808.1297]

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.

The input parameters for the different modes are coming from the global fit in the kinetic scheme, translated to the scheme needed per each model. We are aware of ongoing discussions on the best way to determine the b-quark mass. For consistency among all the measurements, we choose the results coming from the fits to the b->clnu and b->sgamma moments.

Determination of Vub (BLNP)

Determination of |Vub| (BLNP)

The |Vub| values are obtained using the HQE input parameter:

obtained from the global fit in the kinetic scheme

BLNP : Vub with HQ parameters from all moments
|Vub | (BLNP)
Experiment Value [10-3] Parameters References Remarks
CLEO (E_{e}) 3.94 +/-0.46 +0.37 -0.33 input Phys.Rev.Lett.88:231803,2002 [arXiv:hep-ex/0202019v1] 2.1 < p < 2.6
BELLE sim. ann. (m_{X}, q^{2}) 4.33 +/- 0.46 + 0.35 - 0.30 input Phys.Rev.Lett.92:101801,2004 [arXiv:hep-ex/0311048v2] mX - Q2, tag with annealing method
BELLE (E_{e}) 4.74 +/- 0.44 + 0.35 - 0.30 input Phys.Lett.B621:28-40 (2005) (arXiv:hep-ex/0504046v2 1.9 < p < 2.6
BABAR (E_{e}) 4.29 +/- 0.24 + 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}) 4.41 +/- 0.30 + 0.42 - 0.37 input Phys.Rev.Lett.95:111801,2005 , Erratum-ibid.97:019903,2006 [arXiv:hep-ex/0506036v3] (Ee-q2)
BELLE (m_{X}) 3.99 +/- 0.26 + 0.30 - 0.25 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}) 4.13 +/- 0.20 + 0.32 - 0.27 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] mX, BRECO tag; other methods (mX-q2 and P+ not used). Cut on the hadronic mass at 1.55 GeV
BABAR (m_{X}-q^{2}) 4.41 +/- 0.29 + 0.36 - 0.31 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] mX q2, BRECO tag; correlation with mX-q2 and P+ is taken into account
BABAR (P^{+}) 3.76 +/- 0.24 + 0.31 - 0.25 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] P+, BRECO tag; correlation with mX-q2 and mX is taken into account
Average +/- exp + theory - theory 4.32 +/- 0.16 + 0.32 - 0.27 chi2/dof = 8.5/8 (CL = 0.39) Plots: eps pdf gif mb input from global fit in the kinetic scheme
The full breakdown of the uncertainties on the average |Vub| above is (all errors quoted in percent):

positive errors: +2.1stat +2.3exp +1.3b2c model +1.4b2u model +5.7HQE param +2.2SF func +0.9sub SF +3.7matching +1.6WA = +8.2tot

negative errors: -2.1stat -2.3exp -1.3b2c model -1.3b2u model -4.5HQE param -2.1SF func -0.9sub SF -3.4matching -1.6WA = -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 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:

obtained from the global fit in the kinetic scheme

|Vub| (DGE)
Experiment Value [10-3] Parameters References Remarks
CLEO (E_{e}) 3.58 +/- 0.42 + 0.26 - 0.20 input Phys.Rev.Lett.88:231803,2002 (hep-ex/0202019) 2.1 < p < 2.6
BELLE sim. ann. (m_{X}, q^{2}) 4.16 +/- 0.44 + 0.24 - 0.14 input Phys.Rev.Lett.92:101801,2004 (hep-ex/0311048) mX - Q2, tag with annealing method
BELLE (E_{e}) 4.56 +/- 0.42 + 0.22 - 0.19 input Phys.Lett.B621:28-40 (2005) (hep-ex/0504046) 1.9 < p < 2.6
BABAR (E_{e}) 4.04 +/- 0.27 + 0.24 - 0.21 input Phys.Rev.D73:012006,2006 (hep-ex/0509040) 2.0 < p < 2.6
BABAR (E_{e}, s^{max}_{h}) 4.01 +/- 0.27 + 0.28 - 0.22 input Phys.Rev.Lett.95:241801,2005 (hep-ex/0506036 (version 3, June 2006)) (Ee-q2)
BELLE m_{X} 4.07 +/- 0.27 + 0.22 - 0.19 input Phys.Rev.Lett.95:241801,2005 (hep-ex/0505088) mX, BRECO tag; other methods (mX-q2 and P+ not used)
BABAR m_{X} 4.25 +/- 0.20 + 0.20 - 0.14 input Phys. Rev. Lett. 100, 171802 (2008)[arXiv:0708.3702v1] mX, BRECO tag; correlation with mX-q2 and P+ analyses is taken into account
BABAR m_{X}-q^{2} 4.24 +/- 0.28 + 0.23 - 0.16 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] mX q2, BRECO tag; correlation with mX-q2 and P+ is taken into account
BABAR P^{+} 3.73 +/- 0.24 + 0.28 - 0.22 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] P+, BRECO tag; correlation with mX-q2 and mX is taken into account
Average +/- exp + theory - theory 4.26 +/- 0.14 + 0.19 - 0.13 chi2/dof = 7.3/8 (CL = 0.51) Plots: eps pdf gif mb input from global fit in the kinetic scheme
The full breakdown of the uncertainties on the average |Vub| above is (all errors quoted in percent):

positive errors: +2.2stat +2.1exp +1.2b2c model +1.3b2u model +0.7alpha_s R_CUT +4.0mb +1.5WA +1.2DGE theory =+5.7tot

negative errors: -2.2stat -2.1exp -1.1b2c model -1.3b2u model -0.3alpha_s R_CUT -2.7mb -1.6WA -0.5DGE theory =-4.7tot

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 and the total rate (mb), 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)

The |Vub| values are obtained using the HQE input parameters:

obtained from the global fit in the kinetic scheme

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}) 3.77 +/- 0.44 + 0.26 - 0.39 input Phys.Rev.Lett.88:231803,2002 (hep-ex/0202019) 2.1 < p < 2.6
BELLE sim. ann. (m_{X}, q^{2}) 4.23 +/- 0.45 + 0.34 -0.35 input Phys.Rev.Lett.92:101801,2004 (hep-ex/0311048) mX - Q2, tag with annealing method
BELLE (E_{e}) 4.61 +/- 0.43 + 0.23 - 0.31 input Phys.Lett.B621:28-40 (2005) (hep-ex/0504046) 1.9 < p < 2.6
BABAR (E_{e}) 4.13 +/- 0.23 + 0.23 - 0.34 input Phys.Rev.D73:012006,2006 (hep-ex/0509040) 2.0 < p < 2.6
BELLE m_{X} 3.93 +/- 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} 4.07 +/- 0.20 + 0.27 - 0.29 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] mX, BRECO tag; other methods (mX-q2 and P+ not used)
BABAR m_{X}-q^{2} 4.29 +/- 0.28 + 0.34 - 0.36 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] mX-q2, BRECO tag; correlation with mX and P+ is taken into account
BABAR P^{+} 3.52 +/- 0.23 + 0.30 - 0.31 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] mX, BRECO tag; correlation with mX and mX-q2 is taken into account
Average +/- exp + theory - theory 3.96 +/- 0.15 + 0.20 - 0.23 chi2/dof = 7.0/7 (CL = 0.43) Plots: eps pdf gif mb input from global fit in the kinetic scheme
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 +1.3ff =+6.3tot

negative errors: -2.3stat -2.2exp -1.2b2c model -1.5b2u model -3.9par. -1.7pert. -2.6q2* -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:

obtained from the global fit in the kinetic scheme

|Vub| (ADFR)
Experiment Value [10-3] Parameters References Remarks
CLEO (E_{e}) 3.49 +/- 0.20 + 0.23 - 0.23 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}) 3.95 +/- 0.42 + 0.22 - 0.22 input Phys.Rev.Lett.92:101801,2004 (hep-ex/0311048) mX - Q2, tag with annealing method
BELLE (E_{e}) 3.25 +/- 0.17 + 0.22 - 0.21 input Phys.Lett.B621:28-40 (2005) (hep-ex/0504046) 2.3 < p < 2.6
BABAR (E_{e}) 3.46 +/- 0.14 + 0.23 - 0.23 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 +/- 0.26 + 0.23 - 0.24 input Phys.Rev.Lett.95:111801,2005 , Erratum-ibid.97:019903,2006 (hep-ex/0506036 (version 3, June 2006)) (Ee-q2)
BELLE m_{X} 3.93 +/- 0.26 + 0.23 - 0.23 input Phys.Rev.Lett.95:241801,2005 (hep-ex/0505088) mX, BRECO tag; other methods (mX-q2 and P not used)
BABAR m_{X} 4.04 +/- 0.19 + 0.24 - 0.24 input Phys. Rev. Lett. 100, 171802 (2008) [hep-ex/0507017] mX, BRECO tag; correlation with mX-q2 and P+ analyses is taken into account
BABAR m_{X}-q^{2} 4.14 +/- 0.26 + 0.23 - 0.23 input Phys. Rev. Lett. 100, 171802 (2008) [hep-ex/0507017] mX q2, BRECO tag; correlation with mX-q2 and P+ is taken into account
BABAR P^{+} 3.45 +/- 0.22 + 0.21 - 0.37 input Phys. Rev. Lett. 100, 171802 (2008) [hep-ex/0507017] P+, BRECO tag; correlation with mX-q2 and mX is taken into account
Average +/- exp + theory - theory 3.76 +/- 0.13 + 0.22 - 0.22 chi2/dof = 17.1/8 (CL = 2.9) 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 +2.4exp +1.2b2c model +1.4b2u model +1.7alpha_s +1.4Vcb +0.6mb +4.4mc +0.9BF +2.9model =+6.8tot

negative errors: -1.8stat -2.3exp -1.3b2c model -1.3b2u model -1.8alpha_s -1.4Vcb -0.6mb -4.2mc -1.0BF -2.9model =-6.8tot

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 HQE input parameter:

obtained from the global fit in the kinetic scheme

|Vub| (BLL) using the (mx-q2) analyses
Experiment Value [10-3] Parameters References Remarks
BELLE breco (m_{X}, q^{2}) 4.97 +/- 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}) 4.67 +/- 0.49 + 0.34 - 0.34 input Phys.Rev.Lett.92:101801,2004 (hep-ex/0311048) mX - Q2, tag with annealing method
BABAR (m_{X}, q^{2}) 4.88 +/- 0.32 + 0.36 - 0.36 input Phys. Rev. Lett. 100, 171802 (2008) [arXiv:0708.3702v1] mX-q2, BRECO tag
Average +/- exp +/- theory 4.87 +/- 0.24 + 0.38 - 0.38 chi2/dof = 0.4/2 (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 +1.4b2c model +2.1b2u model +3.0Strf +3.0Pert +4.5Sf +4.0H.O. = +9.0tot

negative errors: -3.2stat -3.8exp -1.4b2c 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) 4.32 +/- 0.16 + 0.32 - 0.27
HFAG Ave. (DGE) 4.26 +/- 0.14 + 0.19 - 0.13
HFAG Ave. (GGOU) 3.96 +/- 0.15 + 0.20 - 0.23
HFAG Ave. (ADFR) 3.76 +/- 0.13 + 0.22 - 0.22
HFAG Ave. (BLL) 4.87 +/- 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_{+} 1.81 +/- 0.28 +/- 0.13 1.37 +/- 0.26 +/- 0.09 0.45 +/- 0.17 +/- 0.06 SL tag, preliminary [arXiv:0805.2408] (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_{+} 1.24 +/- 0.23 +/- 0.06 0.81 +/- 0.19 +/- 0.04 0.41 +/- 0.11 +/- 0.02 Breco tag, preliminary (input)
BABAR SL tag: B ^{0} \rightarrow \pi^{-} l^{+} \nu 1.38 +/- 0.21 +/- 0.07 0.92 +/- 0.16 +/- 0.05 0.46 +/- 0.13 +/- 0.03 SL tag, preliminary [arXiv:0805.2408] (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 1.12 +/- 0.18 +/- 0.05 0.85 +/- 0.16 +/- 0.04 0.26 +/- 0.08 +/- 0.01 Preliminary, Breco tag (input)
Average: B ^{0} \rightarrow \pi^{-} l^{+} \nu 1.34 +/- 0.06 +/- 0.05 0.93 +/- 0.05 +/- 0.04 0.37 +/- 0.03 +/- 0.02 Plots: eps pdf gif   chi2/dof = 3.48/9 (CL = 0.94)

Vub from B -> pi l nu average

Exclusive |Vub| determination

The partial BF quoted above along with theoretical calculations of the form factor normalization can be used to determine |Vub|; a few recent calculations are shown below. Note that the FNAL04 and HPQCD unquenched LQCD calculations are not entirely independent, and we do not use their quenched results as they are superseded by their unquenched results. The Ball-Zwicky calculation is based on light-cone sum rules.  At this time we do not attempt to average the |Vub| results or select a best value.

The errors on |Vub| are experimental and theoretical, respectively.

Vub from B -> pi l nu average
FF calculation Vub [10-3] q2 range FF norm (ps-1) Reference
Ball-Zwicky q^{2} < 16 3.34 +/- 0.12 +0.55-0.37 <16 GeV2 5.44 +/- 1.43 Phys. Rev. D71:014015 (2005) [hep-ph/0406232]
HPQCD q^{2} > 16 3.40 +/- 0.20 +0.59-0.39 >16 GeV2 2.07 +/- 0.57 Phys.Rev.D73, 074502 (2006), Erratum-ibid.D75:119906,2007 [hep-lat/0601021]
FNAL q^{2} > 16 3.62 +/- 0.22 +0.63-0.41 >16 GeV2 1.83 +/- 0.50 Nucl.Phys.Proc.Suppl.140:461-463,2005 [hep-lat/0409116]

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

Consistent results are obtained using quenched Lattice QCD calculations (eg. arXiv:hep-lat/0011065). 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 untagged: B^{0} \rightarrow \rho^{-} l^{+} \nu 2.69 +/-0.41 +/- 0.63 Phys. Rev. D 61, 052001 (2000) [hep-ex/9905056] (input)
CLEO untagged: B^{0} \rightarrow \rho^{-} l^{+} \nu 2.93 +/-0.37 +/- 0.37 PRL 99, 041802 (2007)[arXiv:hep-ex/0703041v2] (input)
BABAR untagged: B^{0} \rightarrow \rho^{-} l^{+} \nu 2.14 +/-0.21 +/-0.55 Untagged, Phys .Rev. D72, 051102 (2005) [hep-ex/0507003] (input)
BELLE B_{reco} tag:: B^{0} \rightarrow \rho^{-} l^{+} \nu 2.56 +/-0.46 +/-0.12 Breco tag, preliminary. Presented at ICHEP08. (input)
BELLE B_{reco} tag:: B^{+} \rightarrow \rho^{0} l^{+} \nu 3.39 +/-0.43 +/-0.13 Breco tag,preliminary. Presented at ICHEP08. (input)
BELLE SL tag: B^{0} \rightarrow \rho^{-} l^{+} \nu 2.17 +/-0.54 +/-0.32 SL tag, Phys.Lett.B648:139-148,2007 [hep-ex/0604024] (input)
BELLE SL tag: B^{+} \rightarrow \rho^{0} l^{+} \nu 2.47 +/-0.43 +/-0.33 SL tag, Phys.Lett.B648:139-148,2007 [hep-ex/0604024] (input)
Average: B ^{0} \rightarrow \rho^{-} l^{+} \nu 2.80 +/- 0.18 +/- 0.16 Plots: eps pdf gif   chi2/dof = 3.6/6 (CL = 0.73)
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 0.64 +/-0.20 +/- 0.30 Preliminary B SL tag [arXiv:0805.2408]
BABAR B+-> eta l+ nu 0.31 +/-0.06 +/- 0.08 Preliminary Untagged
BABAR B+-> eta' l+ nu 0.33 +/-0.60 +/- 0.30 Preliminary Breco [hep-ex/0607066]
BABAR B+-> eta' l+ nu <0.47 @ 90% CL Preliminary B SL tag [arXiv:0805.2408]
BABAR B+-> omega l+ nu 1.14 +/-0.16 +/-0.08 Preliminary untagged
BELLE B+-> omega l+ nu 1.19 +/-0.32 +/-0.05 Preliminary Breco


Last update: 2010/Jan/15 Concezio Bozzi fix typo in LLR results for inclusive Vub.
Previous update: 2009/Apr/8 David Lopes Pegna (Bug fix).