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A big success with more than 200 participants. AIM OF THE WORKSHOP Make an overall status of our knowledge of the CKM parameters at the end of the era.

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Presentation on theme: "A big success with more than 200 participants. AIM OF THE WORKSHOP Make an overall status of our knowledge of the CKM parameters at the end of the era."— Presentation transcript:

1 A big success with more than 200 participants

2 AIM OF THE WORKSHOP Make an overall status of our knowledge of the CKM parameters at the end of the era of CLEO, LEP, SLD, TeVatron I (reach consensus to start from common base) Try to define priorities for theoretical developments and future measurements : - in a short timescale (B-Factories/TeVatron II) - in a longer timescale (bridging today LHC)

3 Working Group I : V ub, V cb and Lifetimes Working Group II : V td, V ts Working Group III : CKM Fits Lattice Data Group (LDG) Forum on Averaging (for PDG + users) Talks on : Charm and Kaon Physics Structure of the Workshop

4 1- 2 /2 A 3 (  i  )  1- 2 /2A 2 A 3 (1-  -i  ) - A 2 1 u c t dsb b d, s b V td,V ts B Oscillations d, s V tb c,u B decays b V ub,V cb The CKM Matrix In the Wolfenstein parameterization 4 parameters :, A, 

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6 To be continued at B-Factories and TeVatron Theoretical assumptions Theoretical uncertainties Possible measurements Theory UT parameters Measurements Error Meaning (discussion) Statistical Methods to extract UT parameters Analysis Methods Analysis Systematic

7 WORKING GROUP I Lifetimes V cb V ub c,u B decays b V ub,V cb

8 Inclusive Determination of V cb b c l V cb Average by LEP Working Groups BR sl +  b V cb

9 Determination of V cb limited by theoretical uncertainties ….. The expression of V cb in the low scale running HQ masses formalism (as an example)* Can these parameters be determined experimentally ? V cb = 0.0415  ( 1 - 0.012  2   0.010 m b + 0.006  s + 0.007  mbmb (  Fermi movement inside the hadron) ( also named  ) 22 V cb    m b  pert  * In “Upsilon expansion” formalism :

10 From CLEO measurements

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12 Other experiments should perform this analysis …….

13 Value agreed at the end of the Workshop Part of theoretical error on V cb becomes experimental from the determination of  2   and m b V cb (inclusive)= ( 40.7 ± 0.7 ± 0.8 ) 10 -3 It was ± 2.0 and of theo. origin !

14 Exclusive Determination of V cb G(w) contains kinematics factors and is known (also  1 and   ) F(w) is the form factor describing the B  D * transition At zero recoil (w=1), as M Q  F(1)  1 Strategy : Measure d  /dw and extrapolate to w=1 to extract F(1) V cb

15 Syst. dominated by the knowledge of the D** (for LEP) F(1) |V cb | 2 22

16 F(1) At the Workshop agreement on F(1) = 0.91±0.04 (Gauss.) 3 determinations

17 What’s next to improve V cb Experimental side: More and new moment analyses B-factories can perform both exclusive and inclusive analyses Theory side : More work on the theory for the  2 ,m b extraction Unquenched F(1) calculations Studies of eventual correlation between inclusive and excluive determinations Form factors measurements in B  D*l

18 Combing the inclusive and the exclusive measurements : V cb = (41.8 ± 1.0 ) 10 -3

19 Challenge measurement from LEP Inclusive determination of Vub Using several discriminant variables to distinguish between the transitions : b  c b  u V ub B  X u l

20 Results from all the LEP experiments

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22 At the Workshop we agreed on V ub (inclusive) = (4.09 ± 0.46 ± 0.36) 10 -3 New determination

23 Exclusive determination of Vub B   l V ub = (3.68 ± 0.55 +0.28 (syst.))10 -3 (in ISGW2 Model) - 0.37 V ub = (3.68 ± 0.14 +0.21 (syst.)± 0.55(theo.))10 -3 - 0.29 Babar CLEO Important theoretical uncertainties from different models NOW, Lattice QCD calculations start to be precise

24 What’s next to improve V ub Experimental side: B-factories can perform inclusive/end-point/exclusive analyses Theory side : More work on the theory for the extraction of inclusive/end-point analyses Lattice QCD calculations for exclusive form factors Correlations between the different V ub determinations Correspondence between D   l and B   l

25 All lifetimes of weakly decaying B hadrons have been precisely measured Very important test of the B decay dynamics Lifetimes

26  (B 0 d ) = 1.543 ± 0.015 ps ( 1.0%)  (B + ) = 1.658 ± 0.014 ps ( 0.9%)  (B 0 s ) = 1.464 ± 0.057 ps ( 3.9%)  (  B ) = 1.208 ± 0.051 ps ( 4.2%) Averages from LEP/SLD/Tevatron (+ B-Factories) The hierarchy was correctly predicted !  (B + )/  (B 0 ) about 5  effect in agreement with theory  (B 0 s )/  (B 0 ) about 1  effect in agreement with theory Is there a problem for  B ?

27 Theory News…..

28 Next improvements :  (B + )/  (B 0 ) from B factories But more important  (B 0 s ) and  (  B ) from TeVatron …. and  B B c,  c Experiment side: Theory side: Improvements of the Lattice QCD calculations

29 mdmd msms WORKING GROUP II Radiative and Leptonic B decays Rare K decays d, s b b V td,V ts B Oscillations

30 Present Future

31 Study of the time dependent behaviour of the Oscillation B 0 - B 0 TextBook Plot

32 Before B-Factories mdmd LEP/SLD/CDF precisely measured the  m d frequency  m d = 0.498 ± 0.013 ps -1 LEP/SLD/CDF (2.6 %) B-factories confirmed the value improving the precision by a factor 2  m d = 0.496 ± 0.007 ps -1 LEP/SLD/CDF/B-factories (1.4%) The final B-factories precision will be about 1% ( 0.004 ps -1 )

33 Combination of different limits using the amplitude methods Combination using A and  A msms  m s excluded at 95% CL A + 1.645  A < 1 At given  m s A = 0 no oscillation A = 1 oscillation Sensitivity same relation with A = 0 1.645  A < 1 Measurement of A at each  m s

34  m s > 14.9 ps -1 at 95% CL Sensitivity at 19.3 ps -1 “Hint of signal” at  m s =17.5 ps -1 but with significance at 1.  Expectation in The Standard Model  m s [14.1-21.6] ps -1 at 95% CL

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39 Very important achievement. The  m s information has to be included in the CKM Fits using the Likelihood Method. ( in the past this was a source of differences between the groups performing CKM fits)

40 WORKING GROUP III CKM Fits Strategies the angle  V ud,V us Two subgroups :

41 1- 2 /2 A 3 (  i  )  1- 2 /2A 2 A 3 (1-  -i  ) - A 2 1 u c t dsb b d, s b V td,V ts B Oscillations d, s V tb c,u B decays b V ub,V cb The CKM Matrix In the Wolfenstein parameterization 4 parameters :, A, 

42 b  u / b  c | V ub \ V ub | 2  2 +    m d |V td | 2 f B d 2 B B d f(m t )  2 +    m d \  m d |V td \ V td | 2 f Bd 2 B B d \ f B s 2 B B s  2 +    K f(A,  B K..) 

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44 Ex : B K = 0.87 ± 0.06 (gaus) ± 0.13 (theo.) Treatment of the inputs Rfit Bayesian p.d.f. from convolution (sum in quadrature) Likelihood Delta Likelihood Likelihood obtained summing linearly the two errors Delta Likelihood [0.68-1.06] [0.76-0.98]At 68% CL

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47 Where the difference is coming from ? Difference comes from how the inputs are treated : At present mainly from: F(1), inclusive V cb, B K Breakdown of the error is important The splitting between Gaussian and theoretical error is crucial and somehow arbitrary Results of the Workshop : theoretical error reduced and origin of the error better defined  K ( V cb 4 * B K )

48 Differences are small and physics conclusions quantitatively the same

49 The difference ( which is by the way small ) on the CKM quantities coming from the different methods, is essentially due to the different treatment of the theoretical errors Using Likelihoods as obtained from linear sum of Exp.+Theo. errors Using Likelihoods as obtained from convolution of Exp. Theo. errors Both methods use the same likelihood Differences almost disappears

50 Another example with sin2  (without  K )

51  [0.14-0.30]  [0.24-0.39] at 95%CL  = 0.220 ± 0.040  = 0.315 ± 0.038 at 68%CL

52 Which are the predictions : sin2 , ,  m s sin2  [0.57-0.81]  [43.6-67.3] o at 95%CL  m s [14.1-21.6] ps -1 sin2  = 0.78 ± 0.08From B  J/  K 0 s First crucial test done

53 Winter 2002 1995 1988 Mainly thanks to measurements done at LEP after the end of data taking

54 What will happen next ? Proceedings by Summer : Yellow Book + simultaneous publication in other laboratories (Slac/Tevatron/Cornell..) We hope with significant improvement from B-factories Next Workshop, late Spring 2003 in UK ( Lake District ) Aim is to have a LHC preparation workshop in year B LHC -2 But may well be need for a further a Workshop before…. B Physics has been intensively studied during last 10 years at LEP/SLD/TeVatron and CLEO and spectacular improvements have been obtained in the last years


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