1-2/2

1-2/2

u

c

d s b

A 3(1--i) -A2t

d, sb

d, s b

Vtd ,VtsB Oscillations

A 3(i)

A2

1Vtb

c,u

B decays

b

Vub,Vcb

Wolfenstein parametrization 4 parameters : ,A,

The CKM matrixThe CKM matrix

2Theory

Experiments at the Z / Experiments at the Z / ((4S4S))

3

pB ~ 1 GeV

pB ~ 30 GeV

Z Z bbbb

(4S)(4S) BB BB

CLEOALEPH

DELPHI

OPAL

BABAR

The DELPHI experiment

pB ~ 0.3 GeV

BELLE

~ 150~ 150 MM

~ 3.4~ 3.4 MM

~ 0.8~ 0.8 MM

4

Event SelectionEvent Selection

Analysed data samples

Lifetime probability

5

Event ReconstructionEvent Reconstruction

Analysed data samples

D mass resolution

Decay distances

6

Discriminant variablesDiscriminant variables

Analysed data samples

~80%~80% ~80%~80%

~80%~80%~46%~46%

QX< 0 QX= 0 23

13

qq2 2 measurementmeasurement

7|Vcb| from

qq2 2 measurementmeasurement

8|Vcb| from

FitFit

9|Vcb| from

Event by event Event by event likelihood:likelihood:

P(q2) P(m)

P(d+) P(d-)

+ Constraints on Nj (except for combinatorial

and D** backgrounds)

Nsignal ddq2

dq2

dNdq2

|Vcb|2 F2(w) K(w)

eff(q2) res(q2) F(w) as function

of the f.f. 2, R1 and R2.Fit F(1)|Vcb| and 2

meas.

Results on simulated eventsResults on simulated events

10|Vcb| from

Generator level Reconstruction level

11|Vcb| from

Results on individual samplesResults on individual samples

Results on individual samplesResults on individual samples

12|Vcb| from

Fixing the BR = (0.67 ± 0.08 ± 0.11)%

DELPHI averageDELPHI average

13|Vcb| from

DELPHI average:DELPHI average:

Results:Results:Increased statistics ( 4)New channel (K- +(0))

Improvements in the reconstruction (Eb, mD*)

Control on background

New observablesNew measurements

Results on Real Data Results on Real Data

14|Vcb| from

Systematic uncertainties Systematic uncertainties

15|Vcb| from

External External parameters parameters K-+X rates: b fragmentation:

Systematic uncertainties Systematic uncertainties

16|Vcb| from

Detector Detector performance performance

Resolution function:

Syst. due to the parameterization:

F(1)|Vcb|2

2.0% 5%

F(1)|Vcb|2

1.0% 3.5%

Including/excluding

K-+ (0)

Systematic uncertainties Systematic uncertainties

17|Vcb| from

Detector Detector performance performance

d±

distributions:

Systematic uncertainties Systematic uncertainties

18|Vcb| from

Signal and background modelling Signal and background modelling

Signal:

Systematic uncertainties Systematic uncertainties

19|Vcb| from

Background modelling Background modelling

D*2

D*1

D1

Model 1 Model 2

q2sim q2sim

Comparison with other measurementsComparison with other measurements

20|Vcb| from

21

SystematicsSystematics

|Vcb| from

Probability distributionsProbability distributions

22D** properties

Probability distributionsProbability distributions

23D** properties

RD/MCRD/MC

24D** properties

Discriminat variablesDiscriminat variables

25D** properties

Discriminat variablesDiscriminat variables

26D** properties

Discriminat variablesDiscriminat variables

27D** properties

Cascade correction factorsCascade correction factors

28D** properties

SystematicsSystematics

29D** properties

R*

Backgr. mass distribution RD/MCBackgr. mass distribution RD/MC

30D** properties

= 0.5 0.2

i = 3, 5

Non-resonant contributionNon-resonant contribution

31D** properties

D** properties 32

Non-resonant contributionNon-resonant contribution

= 0.42%

H.-Y. Cheng et al. PRD48 (‘93) 3204

DD contribution contribution

33D** properties

EfficienciesEfficiencies

34D** properties

Fit Fit m wrong sign candidatesm wrong sign candidates

35D** properties

Fit Fit m RS cand. for 0.25 < R < 0.70m RS cand. for 0.25 < R < 0.70

36D** properties

DDss spectroscopy spectroscopy

37D** properties

OPE formalismsOPE formalisms

38

11, , 22

, , GG

11, , 22,, i (i=1,4)i (i=1,4)

DD ,, LSLS

Energy of light quarks and gluons (related

with mmbb, m, mcc )

11 ( ) Kinetic energy of the b quark inside

the meson

22 (GG) = chromo-magnetic coupling

(MB*-MB)

22

22

22 22

33 33

|Vcb| from inclusive decays

Pole mass expansionPole mass expansion

Kinetic mass (Kinetic mass (=1GeV)=1GeV)

Can be measured

Spectral momentsSpectral moments

39|Vcb| from inclusive decays

Inclusive observables Inclusive observables O O

CLEO

CO

NF 9

8-2

1

PRL 87 251807 ’01PRL 87 251808 ’01

PDG2002

|Vcb|=(40.8 0.5 2.5) 10-3

|Vcb|=(40.4 0.5 0.5 0.8) 10-3

CLEOCLEO

PDG2000

= (0.35 ±0.07±0.10) GeV 1=(-0.236 ±0.071±0.078) GeV2

Photon and lepton energy (E, El),Mass hadronic distribution (Mx), ...

ssbb

q2

ccbb

Expressed in terms Expressed in terms of the same of the same theoretical theoretical parametersparameters

Moments of the Moments of the D** D** distributiondistribution

40|Vcb| from inclusive decays

Inclusive b semileptonic decays

@ LEP

78% Bd , B- 22% Bs , b

22% D 50% D*

28% D**

Exclusive processes

Moments of the total hadronic mass distribution in bc -

Inclusive decay width determination

Study of D** properties

Known

Systematics on momentsSystematics on moments

41|Vcb| from inclusive decays

Combining information on momentsCombining information on moments

Moments

Moments of the lepton energy spectrum by DELPHI

(DELPHI 2002-070-CONF-604)

Combined fit to the 3 first moments

of hadronic and leptonic moments

Two formalismsmmqq

polepole

mmqqkin kin (q)(q)

Included s and (1/mb)3 corrections

Constraints from external results

2 fit to 6 moments

s = 0.22 ± 0.01

42

Pole mass formalismPole mass formalism

43Moments

Fixing

Constraints from

and

= 0.35 ± 0.07 ± 0.10 GeV1 = - 0.238 ± 0.071 ± 0.078 GeV2

= 0.53 ± 0.09 GeV1 = - 0.36 ± 0.09 GeV2

BABARBABAR

CLEOCLEO

Comparison with other measurementsComparison with other measurements

44Moments

|Vcb| (inclusive)

Control on non-perturbative corrections up to O(1/mb) 3

Well defined scheme

Remaining perturbative corrections ~ 1 %

Error of |VError of |Vcbcb| ~ | ~ 2%2%

Updated results Updated results

|Vcb| from moments 45

Using the numerical expression of the Using the numerical expression of the slsl advised by N. Uraltsev :advised by N. Uraltsev :

New moment expressions by P. Gambino :New moment expressions by P. Gambino :

|Vcb| from moments 46

BPS limitBPS limit

Allows an accurate extraction of

N. Uraltsev

(Bogolmo’nyi-Prasad-Sommerfeld)

47Moments

The bThe b quark mass quark mass

Ph.D. M.J. Costa

Ph.D. P. Tortosa

This result

Summary and conclusions Summary and conclusions

48Summary and conclusions

|Vcb| from

Competitive with LEP, CLEO and Competitive with LEP, CLEO and bb--factoriesfactories

Errors of |VErrors of |Vcbcb| dominated by the | dominated by the theorytheory

Improves the previous result from Improves the previous result from DELPHIDELPHI

Large dispersion between results from several Large dispersion between results from several experiments experiments Need for more measurements Need for more measurements

Measurement of Measurement of bb s.l. decays to higher mass states s.l. decays to higher mass states

Need measurements of form factors, production rates, Need measurements of form factors, production rates, BR’s… BR’s…

Summary and conclusions Summary and conclusions

49Summary and conclusions

D** properties

Measurement of the production rates of D**Measurement of the production rates of D**

Study of the D** mass distributionStudy of the D** mass distribution First determination of DFirst determination of D11* properties in B s.l. decays* properties in B s.l. decaysCompatible results of DCompatible results of D00* properties* properties

Measurement of the 3 first moments of the hadronic Measurement of the 3 first moments of the hadronic massmass distributiondistributionFirst measurements at low pFirst measurements at low pCompatible result with CLEO and BABAR Compatible result with CLEO and BABAR check OPE check OPE consistencyconsistency

Increased stat., improved Increased stat., improved syst. syst. D** D** DD production limits production limits

|Vcb| from the inclusive decay width

Accurate determination of |VAccurate determination of |Vcbcb||

Development of the kinetic mass schemeDevelopment of the kinetic mass scheme

Combined fit to 6 DELPHI momentsCombined fit to 6 DELPHI moments

Quark masses determinationQuark masses determination

Proximity to the BPS limitProximity to the BPS limit

Control of non-perturbative parametersControl of non-perturbative parameters

50Summary and conclusions

Summary and conclusions Summary and conclusions