A. Oyanguren (B A B AR Collaboration) LAL – Orsay (Marie Curie EIF)

A. Oyanguren (BABAR Collaboration)

LAL – Orsay (Marie Curie EIF)

3/11/05 - Physikalisches Institut, Universität Bonn

OutlineOutline

A. OyangurenA. Oyanguren3/11/05 - Physikalisches Institut, Universität Bonn3/11/05 - Physikalisches Institut, Universität Bonn 22

The CKM matrixThe CKM matrix

Semileptonic decays ofSemileptonic decays of bb quarksquarks

Exclusive |VExclusive |Vcbcb||

Semileptonic decays of Semileptonic decays of cc quarks quarks

SummarySummary

Inclusive |VInclusive |Vcbcb|| Moment analysisMoment analysis

D** statesD** states

Calibrating Lattice-QCDCalibrating Lattice-QCD


The CKM matrix:The CKM matrix:

A. OyangurenA. Oyanguren 333/11/05 - Physikalisches Institut, Universität Bonn3/11/05 - Physikalisches Institut, Universität Bonn

Weak interactions of Weak interactions of quarksquarks in the SM: in the SM:

VVCKMCKM =Vud Vus Vub

Vcd Vcs Vcb

Vtd Vts Vtb

mmq q + V+ Vqq’qq’ 10 fundamental parameters of the Standard Model 10 fundamental parameters of the Standard Model


A. OyangurenA. Oyanguren 44

~

1-2/2+O(4)

+O(5) 1-2/2+O(4)

A3(1--i)+O(5)

-A2+O(4)

A 3(i)

A2

1+O(4)

Wolfenstein Parameterization

3/11/05 - Physikalisches Institut, Universität Bonn3/11/05 - Physikalisches Institut, Universität Bonn

VVCKMCKM =Vud Vus Vub

Vcd Vcs Vcb

Vtd Vts Vtb

VVCKMCKM

The goal:The goal: Understand the SM Understand the SM picturepicture

to be able to find to be able to find New PhysicsNew Physics signatures signatures

In the SM: In the SM: VVCKMCKM unitaryunitary 4 free 4 free parametersparameters

= |Vus| = 0.2227 0.0017

The Unitarity Triangle (UT)The Unitarity Triangle (UT)


Other approaches: http://www.slac.stanford.edu/xorg/ckmfitter

Vud Vus Vub

Vcd Vcs Vcb

Vtd Vts Vtb

VVududVVubub* + V* + VcdcdVVcbcb* + V* + VtdtdVVtbtb* =0* =0

Overconstrain the UTOverconstrain the UTThe idea:The idea:

VVcbcb and and VVub ub have ahave a key role key role

determineddetermined from tree level from tree level processesprocesses

The The unitary clockunitary clock

Vud Vcd Vtd

Vus Vcs Vts

Vub Vcb Vtb

*=

(0,0) (1,0)

(,)

The problemThe problem


quarks are confined inside hadrons... quarks are confined inside hadrons... The problem:The problem:

Instead of :Instead of :

Vcb

We deal with :We deal with :

Vcb

The theoretical toolsThe theoretical tools


sl sl = = |V|Vxx’xx’||22 f f (theory)(theory)

VVxx’xx’

q2

X’X’xx

Exclusive processes:Exclusive processes:Inclusive processes:Inclusive processes:



Exclusive processes:Exclusive processes:

Vcd

Parameterized by form factors

Heavy Quark Effective TheoryHeavy Quark Effective Theory

For heavy quarks For heavy quarks expansions in 1/m expansions in 1/mQ Q flavour and spin flavour and spin symmetriessymmetries relations between form factorsrelations between form factors

Lattice-QCDLattice-QCDQCD computations QCD computations form factor calculationsform factor calculations

Difficult to put quarks of different mass in the latticeDifficult to put quarks of different mass in the lattice Need calibration Need calibration



Inclusive processes:Inclusive processes: for heavy quarksfor heavy quarks

ff( ( parameters related with parameters related with bb quark properties inside the quark properties inside the hadron hadron )) kinetic energy, spin...kinetic energy, spin...

OOperatorperator P Productroduct E Expansionxpansion

x=

Measurement of moments:Measurement of moments:

Some inclusive observablesSome inclusive observables O O depend on the same depend on the same parametersparameters

(For instance:(For instance:HbHc

: the lepton energy, the mass distribution of HC))

Same parameters for Same parameters for bbcc and and bbuu transitions transitions

Vcb

Measuring VMeasuring Vcbcb


The experimentsThe experiments


Z Z bbbb

BELLE

CLEOCLEO (III)

BABAR

ALEPH

DELPHI

OPAL

PPBB~ 1GeV~ 1GeV

PPBB~ ~ 0.3GeV0.3GeV

PPBB~ 30GeV~ 30GeV

(4S)(4S) BBBB

Exclusive measurement of Exclusive measurement of |V|Vcbcb||


Known function

Form factor of the Form factor of the B B DD* transition* transition

FFD*D*(1)= 0.91 (1)= 0.91 0.04 0.04 ((1/ m1/ mQQ ) )nn and QCD corrections and QCD corrections

FFD*D*(1)=1(1)=1 Normalized by HQET (mNormalized by HQET (mQ Q ) at q) at q22maxmax

The shape parameterized with a form factor slope The shape parameterized with a form factor slope 22



m= m(D0) -m(D0) ~ m(soft)

DD0 0 softsoft

B B D* D* --

D*D*++ - - -- candidates candidates

D0 K-+

Eur. Phys. J. C33 (2004) 213

D0 K-+(0)

D0 K- + - +



World averageWorld average |Vcb|=0.0413 0.0010 0.0020

Inclusive measurement of Inclusive measurement of |V|Vcbcb||


sl incl = B (BXc)/B = |Vcb|2 f ( )

B = 1.568 0.009 ps

B (BXc) = (10.70

0.14)%

|Vcb|

|Vcb|< 1%

Need the same accuracy Need the same accuracy inin

f ( ) f ( )

What is What is Xc? ?

Ex:Ex: Studying the Studying the XXcc hadronic mass hadronic mass distributiondistribution

Getting these parameters from other observables:Getting these parameters from other observables:

The hadronic system The hadronic system XXcc


21%

52%

27%

??

D

D*

D**

HQET:

Ground Ground statesstates

Broad Broad statesstates

Narrow Narrow statesstates

D** mass distribution D** mass distribution


Exclusive reconstruction of Exclusive reconstruction of

Right sign Wrong sign

D(*) contributions

Found < 0.22%

Right sign

Wrong sign

ALEPH [ZP C73 (97) 601]

D** mass distribution D** mass distribution


(constrained)

Narrow states

Broad states

(CDF normalized to the # DELPHI entries)

DELPHI fit superimposed to DELPHI fit superimposed to CDF dataCDF data [PRD 71 (05) 051103]

considering

BD1,D*1 D(2015)%

BNR= (0.23 0.35 0.44)%sNR= (5.0 7.0) (GeV/c2)-1

B D*0= (0.42 0.33 0.22)%

D*0= 260 130 130 MeV

B D*1= (1.24 0.25 0.27)%

mD*1= 2445 34 10 MeV

D*1= 234 74 25 MeV

B D1= (0.56

0.10)%B D*

2= (0.30 0.08)%

CERN-EP-PH-2005-015

|V|Vcbcb|| from Moments from Moments


Moments of the hadronic mass distribution

Moments of the lepton energy spectrum++

Fixing ( ~ MB*-MB ) , and using constraints on mb and mc 22GG

33LSLS



LEP B(BXc)

OPE parameters from DELPHI

Theo. uncertainty

Phys.Lett. B556 (2003) 41



The big success of OPE

(hep-ph/0507253)

Something puzzelingSomething puzzeling


B (B narrow (jq=3/2) ) >> B (B broad (jq=1/2) )

Large 1/mLarge 1/mcc contributions in the theoretical contributions in the theoretical predictions? predictions?

Measured broad component not (only) jMeasured broad component not (only) jqq=1/2? =1/2? ( 0’, ( 0’,

L>1 states?)L>1 states?)

Theoretical predictionsTheoretical predictions (OPE values, sum rules, lattice QCD)(OPE values, sum rules, lattice QCD)

B (B0 D**) = (2.7 0.7 0.2)%

B (B0Xc) - B (B0D) - B (B0D*) = (2.9 0.3)%

B (B narrow ) < B (B broad )

With narrow states only accounting for (0.86 With narrow states only accounting for (0.86 0.13) % 0.13) %

Decays of Decays of c c quarksquarks


Lattice-QCDLattice-QCD


QCD computations in a space-time latticeQCD computations in a space-time lattice

Current Lattice-computers Current Lattice-computers ~ teraflop = 10~ teraflop = 101212 operations/sec. operations/sec.

Impressive accurate resultsImpressive accurate results

parameters: parameters: ss and quark masses and quark masses

Ex:Ex: new result of new result of ffB B = 216 = 216 22 MeV (HPQCD) affecting 22 MeV (HPQCD) affecting mmdd

|V|Vtdtd| accuracy from 16% to 11% | accuracy from 16% to 11%

Difficult to put together quarks of very Difficult to put together quarks of very different mass different mass approximations approximations

Computations need to be confronted with experimental results

Difficult to include dynamical quark-pairs Difficult to include dynamical quark-pairs unquenchedunquenched

matrix elements: decay constants, form factors...matrix elements: decay constants, form factors...a

d

Semileptonic decays of Semileptonic decays of c c quarksquarks


Vud Vus Vub

Vcd Vcs Vcb

Vtd Vts Vtb

In the In the charmcharm sector: sector:

VVcdcd, , VVcscs Constrained from Constrained from measurements of the two first rowsmeasurements of the two first rows

Vcd

Using exclusive semileptonic decays of charm hadrons

to measure form factors and validate Lattice QCD

results

Parameterized by form factors


High accuracy needed to measure the q2-

dependence

DDK K andandDD decaysdecays


Phys. Lett. B317 (1993) 647Phys. Lett. B317 (1993) 647


Lattice QCD form factorsLattice QCD form factors


(D(DKKDD))

Fermilab + MILC, hep-ph/0408306


BES, Phys. Lett. B597 (04) 39



Improve results on B decaysImprove results on B decays

Calibrate Lattice QCD resultsCalibrate Lattice QCD results

Charm Semileptonic Decays:Charm Semileptonic Decays:

|V|Vubub|| measurement:measurement: ff ,, f fBB ,, f fB* B* ,, g g

B*B*BB


Experimental setupsExperimental setups

(3770) @ charm factories

(4S) @ B factories

BBAABBARAR

BELLEBELLE

CLEO-cCLEO-cBES-IIIBES-III


BB DD


Experimental setupsExperimental setups

(3770) (4S) ccSome advantages and disavantagesSome advantages and disavantages

Very large DD (~6

nb) Low multiplicity

Small background

Well known EStill few data

Large cc (~1.3 nb)Very large statistics

Vertex separation

Fragmentation (c D* = 26%)

Background

DD


Experimental techniquesExperimental techniques

At the (3770) Unique kinematics:

Tagged D

s.l. channelU=Emiss-pmiss

E=Ebeam-ED

U=Emiss-pmiss (GeV)

U=Emiss-pmiss (GeV)

p (G

eV

)

Ev

en

ts/5

Me

v

D K e

D e

No PID

CLEO-c hep-ex/0408077CLEO-c hep-ex/0408077

MD (GeV)

Ev

en

ts/1

Me

v CLEO-cCLEO-c10183 112

CLEO-cCLEO-c

60 pb-1

Expected resolution on q2 ~ 0.03 GeV2

D e


Preliminary


At the (4S)

D*+ D0

+

bb/cc separation event shape variables

50904 evts

Ev

en

ts/1

.6 M

ev

m (GeV)

19.5 fb-1

BB

cc

from all particles in the event

E estimation

m (GeV)

Ev

en

ts/2

.7 M

ev

Resolution on q2 found ~ 0.05-0.25 GeV2

q2 = (p+ p)2 = ( pD – pK )2

GeV

Background contribution

data

D K e

Continuum events: e+e- cc



0.4 0.22 0.03 0.05-0.25

10K 6K 1800 90K 30K 450K

0.9K 0.3K 175 9K 3K 45K *

20066.7 fb-1 60 pb-1 3 fb-1 ?? 20 fb-1 300 fb-1

Phys.Lett. B607 (2005) 233-242

D K form factor byFOCUSFOCUS with 6K events

Comparisons:

BaBar 5 times morestat. only with 20 fb-1 (Run1)

And good q2 resolution

*Challenge: background suppression


SummarySummary

Charm Semileptonic DecaysCharm Semileptonic Decays provide a way to provide a way to calibrate calibrate Lattice-QCD Lattice-QCD computationscomputations


|V|Vcbcb|| accuracy is at theaccuracy is at the 1.2% 1.2% level level (world (world average)average)

by using by using inclusive inclusive decays and decays and OPEOPE

ImproveImprove |V|Vubub||

|V|Vcbcb|| and and |V|Vubub|| are key elements of the are key elements of the CKMCKM matrix matrix

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A. Oyanguren (B A B AR Collaboration) LAL – Orsay (Marie Curie EIF)

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