1. Introduction
All results and input files are available at 


In the  following (in no particular  order), the updates  for PDG 2003
with respect to PDG 2002 and the winter conferences '03 are discussed.

2. Changes to common parameters
The branching fractions are the same as for the winter 2003 update
(which were updated wrt to the previous 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
   dssR       0.64          +0.11       -0.11    ! D** !mod 033103
The lifetimes and ratios have been updated: 
   tb0        1.537         +0.015     -0.015    !x B0 lifetime !mod 033103
   tbplus     1.671         +0.018     -0.018    ! B+ lifetime !mod 033103

This implies changes for f0/f+ and chi: 
   fbpb0      1.053         +0.055     -0.055    ! Y(4S)->B+B-/Y(4S)->B0B0bar !mod 033103
                                                 ! bpb0=1.072, t+/t0= 1.066 (PDG2002) 
                                                 ! t+/t0= 1.085 (PDG2003) 
   chi        0.089         +0.004     -0.004    ! chi=chi_d*f0, (chi_d=0.182) !mod 033103
                                                 ! f0 = 0.487
The fractions at LEP were updated: 
   fbd        39.0          +1.3       -1.3      ! Bd fraction !mod 033103
   fbs        10.1          +1.3       -1.3      ! Bs fraction !mod 033103

3. |Vcb|*F(1)
The two  measurements of  OPAL (exclusive and  partial reconstruction)
are  included separately  in  the average.   The  measurement of  CLEO
(PRD51, 1014) has been superceeded by (PRL89, 081803).

The production ratio  of B+ vs. B0 mesons on  the Upsilon(4S) has been
traditionally set to  f+/f0 = 1. This quantity  is now being measured,
and we  include the central value and  the error (see above)  on it in
the averages.  This affects the  Belle measurement since f+/f0 was not
included  in  their paper.   CLEO  fits directly  for  it,  and the  B
fractions were always included the LEP measurements.  f+/f0 results in
an   overall  normalization  correction,   and  gives   a  (currently)
non-negligible contribution of 2.75% to the systematic error of Belle.
This correction increases Belle's central value for |Vcb|*F(1).

4. BF(B0 -> D*+ l nu)
Significant changes here: 

 o The two measurements of OPAL (exclusive and partial reconstruction)
   are included  separately in the  average.  

 o  The measurement  of CLEO  (PRD51,  1014) has  been superceeded  by
   (PRL89,  081803).  

 o The measurements  of ARGUS (ZPHY C57, 533 and  PLB324, 249) as well
   as the very  old CLEO measurement (PRL63, 1667)  have been excluded
   to have a consistent data set (with the |Vcb|*F(1) average).

A correction  for f+/f0  (see above) is  applied. Again,  this affects

The LEP results  are scaled up due to changes  in the input parameters
(with respect to  the averages for the winter  conferences 2003), most
notably due to the fraction of Bd at LEP:

   Parameter    winter 03   PDG 03     winter 03 BF
   fbd          40.1%       39.0%       5.45
   dssR         0.70        0.64        5.49

where the new average BF is now 5.53 +/- 0.23. In the table above, the
column  "winter  03  BF"  gives  the  average  BF  obtained  with  all
parameters at the PDG03 default  except the parameter mentioned in the
first column.

5. |Vcb|*G(1)
Same update  as for 3./4.  (see above). 

6. B0 -> D l nu

In  all experiments,  the dominating  error is  uncorrelated.  Include
f+/f0  for Belle (fbpb0),  but not  CLEO (they  fit directly  for it).
Systematics for D* BF are only given for the Aleph analsis (dst).  The
remaining D  BF sytematics are lumped together  (dkpp). The correlated
BG (corrbg) is  everything associated with D* not  covered by the form
factor (dstf).

7. BF(B -> X l nu) on the Upsilon(4S)
New measurements  by Belle (PLB(547),181)  and BABAR (PRD(67),031101).
Removed the  old measurement of CLEO  (PRD(45), 2212) since  it is not
lepton-tagged but "model dependent".

We now  include a  correction to chi  = chi_d*f0  as f0 !=  0.5.  This
changes  all central  values.   The variation  is  largest for  CLEO's
result, since they used the average of their and ARGUS's chi_d. ARGUS'
chi_d is their own value which is close to the current world average.

The average changes  from 10.66 -> 10.70 if the  correction for chi is
included. The variation  of the results were taken  from the BABAR (by
rerunning the  analysis with a different  chi); the same  error on the
final result is applied for the other analyses.