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A. Oyanguren

A. Oyanguren. ( IFIC -Valencia). EPS 2003, Aachen. l. q 2. n l. b. c. V cb. Introduction. Exclusive.  sl =. Inclusive. Need lifetime measurements. Exclusive measurement limited by theory. Study of form factors. Inclusive measurement analyzed using OPE. Study of moments.

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A. Oyanguren

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

  2. l q2 nl b c Vcb Introduction Exclusive sl = Inclusive Need lifetime measurements Exclusive measurement limited by theory Study of form factors Inclusive measurement analyzed using OPE Study of moments EPS 2003, Aachen 1 A. Oyanguren

  3. Introduction B semileptonic decays @ DELPHI: l- l K- D*+ *+ Z  qq B0 + D0 - D0 + B  3mm bb / hadrons  22% EB  0.7 Ebeam  30 GeV EPS 2003, Aachen 2 A. Oyanguren

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

  5. tB+ = 1.624  0.014stat.  0.018sys. ps tB0 = 1.531  0.021stat.  0.031sys. ps tB+/tB0 = 1.060  0.021stat . 0.024sys. ps Lifetimes B+/B0 lifetimes: EPS 2003, Aachen 4 A. Oyanguren

  6. |Vcb| (exclusive) From decays : Known function (Phase space) Form factor for B  D* Normalized by HQET (mQ  ) at q2max (w = 1)  Finite mQ and QCD corrections  FD*(1)=1 FD*(1)= 0.91  0.04 EPS 2003, Aachen 5 A. Oyanguren

  7. |Vcb| (exclusive) D* - lepton candidates: Bd D*+l-l 0 D0 soft K-+ K-++- K-+(0) & DELPHI PLB510 (’01) 55 F(1)|Vcb| = (37.7  1.1  1.9) 10-3 2 = 1.39  0.10  0.33 BR = (5.39  0.11  0.33)% DELPHI average |Vcb| = 41.4  (1 ± 0.029expt. ± 0.051syst. ± 0.043theo. ) 10-3 FD*(1) EPS 2003, Aachen 6 A. Oyanguren

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

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

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

  11. M1= <m2H - m2D> = 0.647±0.046±0.093 (GeV/c2)2 M2= <(m2H - m2D)2> =1.98±0.23±0.29 (GeV/c2)4 M2’=<(m2H- <m2H>)2>=1.56±0.18±0.17 (GeV/c2)4 M3’=<(m2H- <m2H>)3>=4.05±0.74±0.31 (GeV/c2)6 Hadronic moments Moments of the hadronic mass Measured <mnH>= pD mnD +pD* mnD* + (1-pD-pD* ) <mnD**> Moments of the lepton energy spectrum  (DELPHI 2002-070-CONF-604) EPS 2003, Aachen 10 A. Oyanguren

  12. G= 0.35  0.05 GeV2 LS= - 0.15  0.15 GeV3 2 3 mb (1GeV) = 4.570  0.082  0.010 0.005 GeV mc (1GeV)= 1.133  0.134  0.019  0.020 GeV  = 0.382  0.070  0.031  0.020 GeV2 D = 0.089  0.039  0.004  0.010 GeV3 kin kin 2 3 mb, mc, , D,G, LS 2 3 2 3 Hadronic moments 4-parameter fit Constraints on mb and mc: kin mb = 4.57  0.10 GeV mc = 1.05  0.30 GeV kin And fixing: Value  error fit  sys. mom.  sys. theo. Unconstrained masses:  kin mb (1GeV)= 4.56  0.15 GeV mb(mb)= 4.21  0.14 GeV (MS) LEP tb, s (mb/2, 2mb) |Vcb| = 42.4  (1 ± 0.015expt. ± 0.019fit. ± 0.010theo. ) 10-3 EPS 2003, Aachen 11 A. Oyanguren

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

  14. + Info EPS 2003, Aachen A. Oyanguren

  15. + Info EPS 2003, Aachen A. Oyanguren

  16. + Info EPS 2003, Aachen A. Oyanguren

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