1. A. Oyanguren EPS 2003, Aachen ( IFIC -Valencia)

2. Introduction EPS 2003, Aachen A. Oyanguren 1 V cb q2q2 cb Inclusive Exclusive Need lifetime measurements Exclusive measurement limited by theory Inclusive measurement analyzed using OPE Study of moments Study of form factors  sl =

3. Introduction EPS 2003, Aachen A. Oyanguren  - D0D0 B0B0  3mm  * + D* +  +  - K-K-  bb /  hadrons  22% E B  0.7 E beam  30 GeV D0D0 B semileptonic decays @ DELPHI: B Z  qq 2

4. EPS 2003, Aachen A. Oyanguren 3 Lifetimes Lifetimes NN based b-vertex D-vertex Int. point Inclusive lifetime measurement: World average:  b = 1.570  0.005 stat.  0.008 sys. ps

5. EPS 2003, Aachen A. Oyanguren 4 B + /B 0 lifetimes:  B + = 1.624  0.014 stat.  0.018 sys. ps  B 0 = 1.531  0.021 stat.  0.031 sys. ps  B + /  B 0 = 1.060  0.021 stat.  0.024 sys. ps Lifetimes Lifetimes

6. EPS 2003, Aachen A. Oyanguren |V cb | (exclusive) From decays : Known function (Phase space) Form factor for B  D*  Normalized by HQET (m Q   ) at q 2 max (w = 1)   Finite m Q and QCD corrections  F D* (1)=1 F D* (1)= 0.91  0.04 5

7. EPS 2003, Aachen A. Oyanguren B d  D* +  -  B d  D* +  -  D 0  soft D* - epton candidates: 0 K-+K-+ K-++-K-++- K-+(0)K-+(0) DELPHI PLB510 (’01) 55 & 6 |V cb | = 41.4  (1 ± 0.029 expt. ± 0.051 syst. ± 0.043 theo. )  10 -3 DELPHI average F D* (1) F(1)|V cb | = (37.7  1.1  1.9)  10 -3  2 = 1.39  0.10  0.33 BR = (5.39  0.11  0.33)% |V cb | (exclusive)

8. EPS 2003, Aachen A. Oyanguren Form factors Form factors 7  b form factor: 0  pK-+pK-+  +  +  - pKspKs 0

9. EPS 2003, Aachen A. Oyanguren  sl = |V cb | 2  m b, m c    Kinetic energy of the b inside the meson  G = chromo-magnetic coupling  (M B* -M B )  D,  LS  ,  G 22  D,  LS 33 To be measured! O.P.E.Theory: 3 3 2 2 8 From inclusive decays :  sl =(0.434  0.008)×10 -10 MeV |V cb | (inclusive)

10. EPS 2003, Aachen A. Oyanguren Signal: Moments of the hadronic mass Included info discriminant variable Included possible D**  D   decays Further studies on systematics 9 ~ 2.1% B  D -  D* -  D** - + ~ 10.5 % ~ 5.5% Hadronic moments Hadronic moments D**  D* +  - From D**  D ( * ) 

11. EPS 2003, Aachen A. Oyanguren Hadronic moments Hadronic moments = p D m n D +p D* m n D* + (1-p D -p D* ) = p D m n D +p D* m n D* + (1-p D -p D* ) Moments of the hadronic mass Moments of the lepton energy spectrum (DELPHI 2002-070-CONF-604)  10 Measured M 1 = = 0.647±0.046±0.093 (GeV/c 2 ) 2 M 2 = =1.98±0.23±0.29 (GeV/c 2 ) 4 M 2 ’= ) 2 >=1.56±0.18±0.17 (GeV/c 2 ) 4 M 3 ’= ) 3 >=4.05±0.74±0.31 (GeV/c 2 ) 6

12. EPS 2003, Aachen A. Oyanguren Constraints on m b and m c : m b = 4.57  0.10 GeV m c = 1.05  0.30 GeV |V cb | = 42.4  (1 ± 0.015 expt. ± 0.019 fit. ± 0.010 theo. )  10 -3 4-parameter fit  s (m b /2, 2m b ) 11 m b (1GeV) = 4.56  0.15 GeV m b (m b ) = 4.21  0.14 GeV Unconstrained masses: kin  (MS) Hadronic moments Hadronic moments m b (1GeV) = 4.570  0.082  0.010  0.005 GeV m c (1GeV) = 1.133  0.134  0.019  0.020 GeV   = 0.382  0.070  0.031  0.020 GeV 2  D = 0.089  0.039  0.004  0.010 GeV 3 2 3 kin m b, m c,  ,  D,  G,  LS 2233 LEP  b, Value  error fit  sys. mom.  sys. theo. And fixing:  G = 0.35  0.05 GeV 2  LS = - 0.15  0.15 GeV 3 2 3

13. EPS 2003, Aachen A. Oyanguren Summary Summary Measurement of |V cb | from Measurement of moments Determination of OPE parameters Precise |V cb | from inclusive decays Most accurate value of  b 12

14. EPS 2003, Aachen A. Oyanguren + Info + Info

15. EPS 2003, Aachen A. Oyanguren + Info + Info

16. EPS 2003, Aachen A. Oyanguren + Info + Info