1. Introduction --------------- All results and input files are available at http://www.slac.stanford.edu/xorg/hfag/semi/pdg03/pdg03.shtml 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 Belle. 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.