All results and input files are available at
In the following (in no particular order), the updates for the winter
conferences 2003 with respect to Summer 2002 are discussed.
Note that all information is here for discussion and not final. It is
provided "as is", to have a starting point. All of your feedback is
All information here is preliminary and confidential. Some of the
results have not yet been approved by their collaborations, so please
do not spread the numbers here. This is only for HFAG-internal
discussion (and eventual approval). Please keep this private.
2. Update of common.param
common.param contains the external input parameters, like lifetimes,
secondary branching fractions, etc.
Modified to PDG 2002 values:
dkp 3.80 +0.09 -0.09 ! D0->K+pi- !mod
dkpp 9.10 +0.6 -0.6 ! D+->K+pi-pi+ !mod
dkpzp 13.1 +0.9 -0.9 ! D0->K+ pi- pi0 !mod
dkppp 7.46 +0.31 -0.31 ! D0->K+ pi- pi+ pi- !mod
dkzpp 2.96 +0.18 -0.18 ! D0->K0 pi+pi- !mod
dnlx 6.87 +0.28 -0.28 ! D0->Xlv !mod
Modified to Olivier's latest values (2003), taken from
tb0 1.539 +0.014 -0.014 !x B0 lifetime !mod
tbplus 1.656 +0.014 -0.014 ! B+ lifetime !mod
Added a parameter for f+/f0, the production ratio of B0/B+ at the
fbpb0 1.072 +0.058 -0.058 ! Y(4S)->B+B-/Y(4S)->B0B0bar !mod
This is PDG 2002 with the old lifetime ratio.
Using PDG2002 lifetime ratio (1.083), I get [fbpb0*(oldratio/newratio)]
fbpb0 1.055 +0.055 -0.055 ! Y(4S)->B+B-/Y(4S)->B0B0bar !mod
Using 2003 lifetime ratio (1.073), I get [fbpb0*(oldratio/newratio)]
fbpb0 1.065 +0.055 -0.055 ! Y(4S)->B+B-/Y(4S)->B0B0bar !mod
NB: o dkzpp changed from 2.70 -> 2.96. This is the most significant
The production ratio of B+ vs. B0 mesons on the Upsilon(4S) has been
traditionally set to 1. This quantity is now being measured, and we
can include the central value and the error on it in the
averages. This will affect B0 -> D*lnu and inclusive s.l. width on the
In the PDG, f+/f0=:r is given. The relevant parameter for the analyses
is f0*N(Upsilon(4S)). f0 = 1/(1+r) with the constraint that f0 + f+=1.
Two setups were tested:
o Use f+/f0 with the error from PDG and use BABAR's systematic
error for both BABAR and Belle.
o Use the calculated f0 (with errors propagated) and use BABAR's
systematic error for both BABAR and Belle.
The scaled results of both experiments are compatible to three
significant digits. The usage of f+/f0 is probably more fool-proof
since no translation has to be done. The only thing to remember is
that the change go into different directions (because f+/f0 != f0).
4. Updates of |Vcb|*F(1) and |Vcb|*G(1)
No new measurement here. Some of the results are rescaled slightly due
to the different input parameters, the average do not change.
The difference in f+/f0 between Belle and CLEO not (yet) corrected.
5. Update of BF(B0 -> D*+ l nu)
There is a new preliminary BABAR measurement.
For reference, last summer's value was BF = (5.39 +/- 0.21)%
(CL=0.053). Without the new BABAR measurement, the new common input
parameters yield BF = (5.41 +/- 0.21)% (CL=0.066). The largest change
is for Aleph, from 5.91% to 5.73%. This is due to the change in the BF
of D0->K0S pi+pi-. The changes of the other measurements are smaller.
Including the new BABAR measurement we get the following.
a) With no correction for f+/f0:
BF = (5.17 +/- 0.03 +/- 0.18)% (CL=0.0289).
b) With correction for f+/f0:
BF = (5.27 +/- 0.03 +/- 0.19)% (CL=0.0638).
6. Inclusive semileptonic branching fraction
The following changes have been made with respect to last summer's
o The measurement of CLEO (PR D45, 2212 (1990)) still included in the
PDG 2002 average is not used since it is based on a fit with prompt
and cascade shapes to the lepton spectrum and does not relie on
event tagging as the other analyses.
o Inclusion of the two preliminary BABAR and Belle results with event
tagging based on a fully reconstructed B decay.
7. Average of inclusive charmless semileptonic branching fraction
This needs to be discussed. Four measurements on the Upsilon(4S) are
CLEO endpoint Phys.Rev.Lett.88:231803,2002
BABAR endpoint hep-ex/0207081
CLEO mX-Q2 hep-ex/0207064
BABAR mX preliminary, to be approved. NOTE: central value "blinded"
There are two choices of results to combine:
o |Vub| is given for all analyses, albeit with different formulae
for BF -> |Vub| and different errors. Would need consistency, but
that can be done.
o Inclusive charmless branching fraction. This is not given in all
papers (absent in CLEO's mX-Q2 analysis). Can be re-computed from
|Vub|. Sometimes, not all errors are given for the full branching
fraction but only for |Vub|. In this case, the relative errors
from |Vub| (x2) are applied to the branching fractions.
Some remarks on this first attempt:
o b->c modeling is done with the same MC simulation (ISGW2, Goity
Roberts, and FF parametrization) in CLEO and BABAR.
o b->u modeling is done with the MC, again (including deFazio/
Neubert for the non-resonant production).
o f_u in the current BABAR endpoint analysis is fully correlated with
o The error of the applicability of b->s gamma to the endpoint
analysis is common to both endpoint analyses.
o The theoretical error in the mX (-Q2) analyses is somewhat
correlated with f_u, as OPE is used in both cases and the
extrapolation factor is dependent on the same input parameters
(Lambda_bar,lambda_1 or mb,a). The theoretical error and the error
due to fu are assumed to be fully correlated.
o The central values used in the non-resonant MC are not stated in
CLEO's hep-ex/0207064, and they do not mention the variation they
applied to estimate the error.
o In hep-ex/0207064, CLEO warns about statistical correlations
between their two analyses. This has not yet been quantified.
No central value for the full BF is given. It would be useful to
get this from CLEO directly.
8. To do and remaining issues
The following will be updated in the next day or two:
o s.l. width and |Vcb| with f+/f0