Beijing 8/05 Charm L1 Ian Shipsey 1

CKM Studies and New Physics Searches with Charm

K-

π-

e+

K+

ν

0

0

0

0

(3770)

,

D

D

D

D K eK π

ψ

ν+ − − +→ →

→Ian Shipsey, Purdue University

Two themes:1) Why Charm Physics allowsB physics to reach its full Potential2) Charm physics as a probe of New physics Beyond the Standard Model

Topical Seminar on the Frontiers of Particle Physics (Beijing)Aug. 13 – 17, 2005

Beijing 8/05 Charm L1 Ian Shipsey 2

Outline of the Lectures

Charm as a Probe of New Physics:MixingCP Violation & Rare Decays

Summary & Outlook

Overview: How Charm Physics Helps B PhysicsPrecision Quark Flavor Physics

Experiments That Contribute To Charm Physics

Precision CKM Physics: LifetimesHadronic DecaysLeptonic Decays and Decay constantsSemileptonic Decays and CKM matrix elementsTests of Unitarity

Lecture1

Lecture2 Charm is a vast

topic I will not cover all of it

Beijing 8/05 Charm L1 Ian Shipsey 3

What we knew before November ‘74:**Search for Charm

M.K. Gaillard, B.W. Lee & J.L. RosnerRev. of Mod. Phys. 47, 277 (1975)

(written before the Nov. Revolution)

What we knew 30 years later:A Cicerone for the Physics of Charm

S Bianco, F.L. Fabbri, D. Benson & I. Bigi Nuovo Cimento 26, 1 (2003) hep-ex/0309021

** Nov. 1974 marked the discovery of the J/ψ ccbar state. This “November Revolution” helped to solidify the Standard Model.

Reviews to develop a Perspective

Beijing 8/05 Charm L1 Ian Shipsey 4

Big Questions in Flavor PhysicsDynamics of flavor? Why generations?

Why a hierarchy of masses& mixings?

Origin of Baryogenesis?Sakharov’s criteria: Baryon number violationCP violation Non-equilibrium3 examples: Universe, kaons, beauty but Standard Model CP violation too small, need additional sources of CP violation

Connection between flavor physics & electroweak symmetry breaking?

Extensions of the Standard Model (ex: SUSY) contain flavor & CP violating couplings that should show up at some level in flavor physics, but precision measurements and precision theoryare required to detect the new physics

Beijing 8/05 Charm L1 Ian Shipsey 5

Testable predictions are now being made:

M(Bc)

Charm decay constant fD

Semileptonic D/B formfactors

Harder- first test July 2005

Hardest- First test July 2005

Precision theory? In 2003 a revolution in Lattice QCDBEFORE AFTER

After 30 years of struggle Lattice QCD demonstrated that it can reproducea wide range of massdifferences and decay constants for the firsttime. These were postdictions.

Easier, the 1st prediction Nov. 2004 - a success.Theory/expt Theory/expt

Beijing 8/05 Charm L1 Ian Shipsey 6

Lattice QCD Prediction Mass of the Bc

lattice agrees with CDF to 2 parts in 1,000

bc

Beijing 8/05 Charm L1 Ian Shipsey 7

Charm Physics: The ContextFlavor physics is in the “sin 2β era’ akin to precision Z. Over constrain CKM matrix with precision measurementsDiscovery potential is limited by systematic errors from non-pert. QCD

LHC may uncover strongly coupled sectors in the physicsBeyond the Standard Model. The LC will study them. Strongly coupled field theories an outstanding challengeto theory. Critical need: reliable theoretical techniques& detailed data to calibrate them

Complete definition of pert. and non-pert. QCD Goal: Calculate B, D, Y, ψ to 5% in a few years, and a few % longer term.

Charm can provide the data to test and calibrate non-pert. QCD techniques (especially true at charm threshold)

This Decade

The Future

The Lattice

Beijing 8/05 Charm L1 Ian Shipsey 8

2005

The discovery potential of B physics is limited by systematic errors from QCD:

Form factors in semileptonic (β) decay ,ub cbV V

Decay constants in B mixing ,td tsV V

D system- CKM matrix elements are tightly constrained to <1% by unitarityWork back from measurements of absolute rates for leptonic and semileptonic

D decays yielding decay constants and form factors to test QCD techniques.thatcan then be applied to the B system. + determinations of Vcs Vcd

Precision Quark Flavor Physics: charm’s role

Bd Bd

In addition as Br(B D)~100% absolute D branching ratios normalize B physics.

ρ

η

|f(q2)|2|VCKM|2

CLEO-c BESIIIprogram

Probe of new physics: Dmxing, DCPV D rare (& strong phases for CKM φ3/γ)

J/ψ probe of glueballs and exotics test of QCD Not covered here

Beijing 8/05 Charm L1 Ian Shipsey 9

Theoretical errorsdominatewidth ofbands

2004

precision QCD calculationstested with precision charmdata

theory errors of afew % on B system decay constants & semileptonicform factors

500 fb-1 @ BABAR/Belle

Precision theory + charm = large impact

+

Beijing 8/05 Charm L1 Ian Shipsey 10

Theoretical errorsdominatewidth ofbands

Now

precision QCD calculationstested with precision charmdata at threshold

theory errors of afew % on B system decay constants & semileptonicform factors

500 fb-1 @ BABAR/Belle

Precision theory + charm = large impact

+

Plot usesVub Vcbromexclusiveecaysonly

Beijing 8/05 Charm L1 Ian Shipsey 11

Lattice predicts fB/fD with a small errrorIf a precision measurement of fD existed (it does not)

Precision Lattice estimate of fB precision determination of VtdSimilarly fD/fDs checks fB/fBs precise once Bs mixing seen

Importance of measuring absolute charm leptonic branching ratios: fD & fDs Vtd & Vts

2 2 2( .) Bd td tbV Vra n fte co st ⎡ ⎤= ⎣ ⎦1.0%(expt)Winter 2005

td tbV Vif was known to 3%

would be known to ~5%Bdf

tdV1

ubV

~15% (LQCD)hep-lat/0409040

~ 100%

PDG04

c

c

D

D

ff

δ

Bd Bd

22( ) / ( .)D cdD

B D const f Vµν τ +++ → =

|fD|2

νλ

|VCKM|2

s inaccessible accessible

B d B

D Ds

f ff f+

td tsV / V

known from unitarity to 1%cdV

ρ

η ~ 16%

D+

Beijing 8/05 Charm L1 Ian Shipsey 12

|f(q2)|2

|VCKM|2

HQS

1) Measure D→π form factor in D→πlν. Tests LQCD D→π form factor calculation.2) BaBar/Belle can extract Vub using tested LQCD calc. of B→π form factor.3) Needs precise absolute Br(D →πlν) & high quality dΓ (D →πlν)/dEπ neither exist.

2 D 2 2cd2 |V | |f (q )|

qdd

π→+

Γ∝

b u l νπB

c d l νπD

Importance of Absolute Charm SemileptonicDecay Rates

When Vub is determined fromexclusive semileptonic (β) decay

β

Vub0.87 30.51(3.76 0.16 )10ubV + −

−= ±form factor

Theory Error 18%Expt. Error 4%

known from unitarity to 1%cdV

2 B 2 2ub2 |V | |f (q )|

qdd

π→+

Γ∝

~ 45%

PDG04

BB

δ

Charm semileptonic decaystest form factor predictions

( )8% precision/ /

Br B lBABAR Belle CLEO

π ν→ (World Average Summer 2005)

Beijing 8/05 Charm L1 Ian Shipsey 13

3exp(41.3 1.0 1.8 ) 10cb theoV −= ± ± ×

Importance of precision absolute charm hadronic branching ratios I

As B Factory data sets grow, & calculation of F improve dB(D Kπ)/dB(D Kπ)

dVcb/Vcb=1.2%

Vcb Zero recoil in B → D*l+ν & B → Dl+ν2* 2 2

2 ( ) ( ) cbd B D F q Vdq

νΓ→ ∝l

2 2max( ) 0.91 0.04F q q= = ±

Lattice & sum rule

ALEPH, DELPHI,L3,OPAL.BABAR/BELLE,ARGUS/CLEO/CDF

(World Average Summer 2005)

Now: several key charm branchingratios have errors between 7-26%

needs B(D Kπ)

becomessignificant

Vub/Vcb from at hadron machines requires:( )( )

-b

-b c

p ν

ν

Γ Λ →

Γ Λ →Λ

l

l

B(/\c→pKπ) poorly known: 9.7% > B >3.0% at 90% C.L

Beijing 8/05 Charm L1 Ian Shipsey 14

( )( )

*+o

o +B

DB1

D

h

h

−

−

Γ →=

Γ →

The importance of precisionabsolute Charm BRs II

HQET spin symmetry test

Test factorization with B → DDs

since D*+→π+Do is most useful mode, this compares Do/D+ absolute rates

Compare Bo→D(*)+h- and B+→D(*)oh- rates to extract color suppressed amplitudes

Need Abs BrDS

To test models of B decay charm branching ratios are important:

Beijing 8/05 Charm L1 Ian Shipsey 15

The importance of precisionabsolute Charm BRs III

Test of the Standard Model. Precision: Z →bb and Z →cc (Rb & Rc)is systematically limited by knowledge ofabsolute charm branching ratios

To understand the Higgs at LHC/LCB(H → bb) B(H → cc)precision will depend on absolute charm branching ratios

Beijing 8/05 Charm L1 Ian Shipsey 16

The Unity of Quark Flavor Physics

CharmPhysics

(Semileptonic& hadronic)

B decays

)( ulvXbBr →)( clvXbBr →

Radiative decays (future)Oscillations

dm∆

sm∆

Form Factors,F(1), duality…

,,, 2πµbc mm

ξ,, BB Bf

Moment analysis...)( γsb →

cb

ub

VV

ts

td

VV

γ

α

β

η

ρ

,..., ρπππ→B

CharmPhysics

(Leptonic)

)()(

πππKBBr

BBr→→

DKB →

Theory

),/( 0KJaCP Ψ+ other charmonium

Kaon Physics

)1(~

)(

ρηε

πυυ

−

−

K

KBr

KB(future)

Plot inspiredBy A. Stocchi

Beijing 8/05 Charm L1 Ian Shipsey 17

Charm physics:1974

Charm discovery SLAC and BNL November 1974

e+ e- multihadron enhancementJ/Ψ width << 2 MeV (beam width)

SPEAR in 1974

Goldhaber, Perl, Richter 1974

hadrons

e e+ −

µ µ+ −

Beijing 8/05 Charm L1 Ian Shipsey 18

Charm Physics: 1974

p Be e e+ −+ →

e e+ −

Broad band probe, clean final state

Beijing 8/05 Charm L1 Ian Shipsey 19

g

ge−

e+

*γ c

c

/J Ψ

glueballs?CLEO-C

γ

's are narrow, insufficient energy to decay toopen charm, (i.e. DD) or (cu)(cu)Ψ

C=-1 easy to produce with virtual photon, but decay into three gluons suppressed

+

Despite this, 88% of / are hadrronic(only the ~12% to e / ) used in sin2 measurements

J decayse µ µ β−

Ψ

Radiative / Br~6% are very useful for glueball searchesJ Ψ

T h e / a s a fro n tie rJ Ψg

g

ge−

e+

*γ

1C = −

c

c

/J Ψ

1C = −

Beijing 8/05 Charm L1 Ian Shipsey 20

The Charmonium Spectrum

L=0 L=1

OpenCharm

Beijing 8/05 Charm L1 Ian Shipsey 21

Open Charm Production at Threshold

D meson discovered 1976 Goldhaber/Trilling (LBL)At Ψ’’ = Ψ(3S) = Ψ(3770)

1L′′Ψ → =0D

0D

( 1)L+ −

0D0D

Mark IIIEvents whereboth D’sare reconstructedcircamid-1980’s

0 0'' ,D D D D+ −Ψ →

The role of the Ψ(3770) in charm physicsis analogous to the role of the Y(4S)in B physics

0

0

,D K

D K

π

π

− +

+ −

→

→

Beam constrained mass

Beijing 8/05 Charm L1 Ian Shipsey 22

Absolute Branching Ratio Measurements at the Y(4S) and ψ(3770)

#X Observed( )efficiency x #D's produced

Br D X→ =

In B decay absolute branching ratios are measured at the Y(4S)

( (4 )) (4 )Y S Y SLdt Nσ =∫ g

(4 ) ( (4 ) ) 2Y S BN Br Y S BB N→ =g

With sufficient statistics, it is possible to eliminate the Y(4S) Br assumption,and complications from the fraction of B+ B+ and B0 B0 at the Y(4S)by tagging (fully reconstructing one B in the event)

( (4 ) ) 1Br Y S BB→ =

( ) #Br B X X→ =

#X Observed( )efficiency x #Btags

Br B X→ =

Full B reconstruction has a low efficiency ε(tag) <0.7%, But is becoming a stapleas B Factory data sets grow. Similarly, charm branching ratios can be measured at the Ψ(3770)

The number of B’s produced iswell known

To measure an absolute DBr must know #D’s produced

Beijing 8/05 Charm L1 Ian Shipsey 23

Absolute Charm Branching Ratios at Threshold

e+ e−

0D

0D

K+

π−

e+

e-

#X Observed( )efficiency x #D's produced

Br D X→ =

Where the # of D’s producedIs the # of tags

tag

X

ψ(3770) → DD

The tag efficiency at theψ(3770) is about 20% as theD has large branching ratios to 2-body final states

ψ(3770) ~6 .6nb ( ~x6 Y(4S))

Meson Factory tagfigure of merit:

-1

-1

(BB) tag Ldt=500fbB Factory ~ 1Charm factory (DD) tag Ldt=3fb

σ ε

σ ε= ∫

∫

Beijing 8/05 Charm L1 Ian Shipsey 24

Open Charm Production

experiments at Ψ(3770) # D’s produced Mark III 9.6 pb-1 2 x 10 4

BES II ~30pb pb-1 6 x 104

CLEO-c (now running, goal) 3 fb-1 4 x 107

BESIII (under construction) 15 fb-1 2 x 108

1 9 8 4 1 9 8 8 2 0 0 0 2 0 0 5 2 0 1 0Y e a r

CLEO-c phys. run

BESII BESIII Construction

BESIIIEngineer & phys. run

MARKIII

0.001

0.01

0.1

1

10

100

1000

10000

J/psi psi(2S) psi(3770) Ds Pairs(4100)

Psi Family

Num

ber o

f Eve

nt (M

illio

n)

MARKIIIBESI/IICLEOCBESIII

As we will see, the Ψ(3770)is by far the best place to determineabsolute charm branching ratiosBut until BESII/CLEO-c recentlyoperated there, nobody had done so since 1984.

Beijing 8/05 Charm L1 Ian Shipsey 25

Charm Hadrons

light lightj L S= +rrrQS

r

lightSr

Lρ

light QJ j S= +rr r

HQET

( )cq

QCD

*

*

Corrections go like /

( ) ~ 142( ) ~ 46

Qm

m m D D MeVm m B B MeV

Λ

∆ = −

∆ = −

Heavy quark (Q) hadrons: Q spin decouples ∝1/mQ. Spin of Q andtotal spin j of light quark are separately conserved quantum numbers.

1/2 (degenerate doublet)lightJ j⇒ = ±

3/2lightj =

1/2lightj =

1/2lightj =

cu cd spectroscopy

The same description works forheavy baryons

L=0 L=1

Similar for cs.. Excitement in 2003 Discovery: DsJ(2317) & DsJ(2460)(Spectroscopy not covered here)

Beijing 8/05 Charm L1 Ian Shipsey 26

Fixed Target + −e e pp E791 FOCUS LEP CLEO BaBar/Belle CDF

Beam Hadron Photon 0+ − →e e Z + −e e pp K-π+ ~ 2 × 104 ~ 2 × 105 ~ 104 /expt. ~ 2 × 105 ~ few 106 ~ 106

σt ~ 40 fs ~ 40 fs ~ 100 fs ~ 140 fs ~ 160 fs ~ 50 fs

Many Experiments Produce Charm

Results used in these lectures have been obtained by the following Collaborations:

In 2003-2005:

BESII CLEO-c Beam (3770)e e+ − → ψ K-π+ ~ 2.7 ×103 ~ 5 x104

σt Not

applicable Not

applicable Note:K-π+ is # reconstructed in published analyses, not total collected.

The B Factories and CDF now have the largest charm samples.

Exceptionally low background charm samples were obtained at BESII & CLEO-c ideal formeasuring absolute charm branching ratios.

udsu

cu

W+

Κ-

π+

D

Common normalizingmode:

Beijing 8/05 Charm L1 Ian Shipsey 27

Charm Production near/at the Y(4S)

D’s move ~150 microns, but, energy of D’s is a prioriunknown and the charm, and anti-charm hadron typesare not strongly correlated

Non-resonant production to all hadrons u,d,s,c σcc≈ 1 nb OFF ON

√s→

↑σ

+ σ(B c) ≈ 1 nb 1+1 =2 nbD, Ds, Λc,Ξc…

e−

e+

*γ c

cglue

anti-charmedhadron

charmedhadron

CLEO

0

0

Reconstructing a D does not mean the charm hadron in the event is a , , , , , or any other ground state or excited charm hadron is also a possibility

S c c cD a D D+ Λ Ξ Ω

absolute charm Br’sdifficult

3 experiments,CLEO #c’s=34x106 produced BABAR,BELLE #c’=x20 CLEO and growing

Beijing 8/05 Charm L1 Ian Shipsey 28

Charm Production at the Z0

Br(Z0 cc) ~ 11%3 x 106 c’s /LEP exptD, Ds, Λc,Ξc…

<p> ~ 40 GeVExcellent reconstruction of

Charm vertices

Main LEP contributions to charm physics: (my opinion)- electro-weak measurements: Rc =(Z0 cc)/ (Z0 had)

AFBc (charge asymmetry in e+ e- cc)

See: http://lepewwg.web.cern.ch/LEPEWWG/- c-quark fragmentation function- Ds decay constant

As at 10GeV, the flavors of charm anti-charm pairs produced in Z0

decays are not correlated absolute charm Br’s are difficult

Will notdiscussIn lecture

Hep-ex9909032

D*

While LEP is no more:Giga Z (ILC at the Z pole)or parasitic has some support

Beijing 8/05 Charm L1 Ian Shipsey 29

Charm at CDF

Great potential if charm stays within the trigger bandwidth: expect107 D0→Κπ reconstructedin 2fb-1

CDF can address D mixing,DCPV and rare decays (the formeris hard and no result has yet appeared)CDF cannot measure absolute branching ratiosas charm mesons are not produced correlated

Summer 2002

Cabbibosuppressed

CDF now ~1fb-1

Charm analysis so faruses <130 pb-1

Online trigger on detached vertices in silicon: designed for beauty (also collects charm)

Beijing 8/05 Charm L1 Ian Shipsey 30

B Factories: ~120 x 106 ccbar pairs / 100 fb−1

Substantial continuum rate (B ⇒ DX rate ~equal, but softer)Hard fragmentation: higher momentum, lower combinatoricsGood with neutral daughters

Charm Factories: ~640 x 103 ccbar pairs / 100 pb−1

Modest Rates; low momenta: silicon not useful hereConstrained Kinematics: very cleanGood with neutral daughters & especially neutrinos

Hadron colliders:Very high rateDetached vertex & lepton triggersLimited modes

Fixed Target (photo production & hadro production)High rateMore modes accessible than collidersLarge boosts good for lifetimes

Summary of Experimental Issues

Beijing 8/05 Charm L1 Ian Shipsey 31

Lifetimes

Naïve spectator model for charm

Muon decay:3

52

192πµmGF

o =Γ

23

52

192 cscF

o VmGπ

=Γ0)32( Γ+=Γc

Scaling from the muon:sc

1365

107102.25.1

105.051 −− ×=×⎟

⎠⎞

⎜⎝⎛=τ

τ(D+) ~1,000 fs τ (D0) ~400 fs. Not too bad. Including baryons lifetimes vary between ~100 and 1000 fs, non-spectator processes and higher order corrections

(700 fs)

µµv

eev

,e µ x 3 colorsud

sc

, , 3e uµ ×, , 3ev v dµ ×

Beijing 8/05 Charm L1 Ian Shipsey 32

Charm Hadron Lifetimes

2 5

3192FG mµ

µ πΓ =

(2 3)charm µΓ = + Γ2 5

23 700

192F c

charm cs charmG m V fsτ

πΓ = ⇒ =

Lifetime needed to compare Br(expt) to Γ (theory)Interpreted within O.P.E.

2 4, ,( ) (1/ ) ( ) (1/ )c spect c PI WAWS c cH O m H O mΓ =Γ + +Γ +

Spectator effects (PI.WA,WS) are O(1/mc3) but phase space enhanced

Brτ

= Γ

D+

Ds+

baryons

Muon decay:

µµv

eev

Naïve spectator model:

τ(D+) ~1,000 fs τ (D0) ~400 fs.

,e udµ

Gross features of lifetime hierarchy can be explained

Beijing 8/05 Charm L1 Ian Shipsey 33

Charm Lifetimes

Charm quarks more influenced by hadronicenvironment than beauty quarks.

Errors on lifetimes are not a limiting factor in the measurement of absolute rates.

D+ 7 ‰, D0 4 ‰, Ds 8 ‰, Λc3%, Ξ 0 10%, Ξ+c 6 %, Ω c 17%

some lifetimes known as precisely as kaon lifetimes.

x10x1.3

PDG2004DominatedBy FOCUS2002 results

SELEX, FOCUS, CLEO E791 E687

PDG2004

)( c+Ξτ

1040 7 fs±

)( 0Dτ

)( +Dτ

)( sDτ

( )cτ Λ

)( 0cΞτ

)( cΩτ

501 6 fs±

410.3 1.5 fs±

442 26 fs±

200 6 fs±

1310112 fs+

−

69 12 fs±

Charm beauty

0

( ) 2.5( )DD

ττ

+

≈ 0

( ) 1.1( )BB

ττ

+

≈ PDG2004

( )psτ ( )psτLifetimes are PDG2004 except Dswhich is a PDG2004 + FOCUS average.

Beijing 8/05 Charm L1 Ian Shipsey 34

# events

Charm meson lifetime measurements are still being improved. Most recently…

Charm baryon lifetimes, less well known new measurements from SELEX τΩc= 69.3 ±14.4±8.6 fs Nucl. Phys. A755 180 (2005) (comparable to World best (FOCUS))B factories well-suited to improving these measurements

New average

Beijing 8/05 Charm L1 Ian Shipsey 35

D Nonleptonic Decays

Nonleptonic decays dominate the total rate

fsucD

fsdcD

5.15.410:)(

9.67.1042:)(

00 ±=

±=++

τ

τ 5.2/ 0 ≈+ ττ

Quarks or hadrons? ….in betweenCompare to kaons and B-mesons:

psdsK

psusK

16.07.178:)(

2012390:)(

00 ±=

±=++

τ

τ 70/ 0 ≈+ ττ

0/ 1.08 0.008τ τ+ = ±

Hadrons

quarks00

( ) : 1643 10

( ) : 1528 9

B bu fs

B bd fs

τ

τ

++ = ±

= ±

Beijing 8/05 Charm L1 Ian Shipsey 36

The lifetime hierarchy (quark diagram level)

1

%83.3~

0

≡∝

→ +−

τ

π

BRA

BRKD

74.0%11.2~

000

=

→

ABR

KD π

For the Do (D+) the two states are distinct (identical) 100% Destructive interference predicts : A = 1 – 0.74 = 0.26Measure: A = 0.54 Difference due to hadronic final state interactions

++ → π0KD

u uc s

ud

u u

c sdu

d dc s

ud

d d

c sdu

++ → π0KD

B decays : small BRs to 2- body final states (phase space)2-body decays dominate D decays (multi-body decays found to be quasi 2 body) Is the D0 D+ lifetime hierarchy understandable in terms of 2 body hadronic decays?

0D K π+ +→

0D K π− +→

0 0 0D K π→

Beijing 8/05 Charm L1 Ian Shipsey 37

…..and at the hadronic level

2/32/10

31

32)( AAKDA +=→ +−π

)32

31)( 2/32/1

000 AAKDA +−=→ π

03 / 2( ) 3A D K Aπ+ +→ =

( ) οο 79003.037.0/ 022/12/3 ±=−=±= δδδAAMany similar cases. Substantial modification of hadronic 2-body BR’s due to FSI.

Rosner hep-ph/9903543

The presence of strong phases between amplitudesis an important ingredient in mixing studies and in CP violation

δδiII eAA =

Simple factorization picture describes 2 body hadronic decays established for B’s. For charm sizeable final state interactions are the norm.

( )2 2 21/2 3/2 1/2 3/2 1/2 3/2 3/2 1/22 cosA A A A A A δ δ+ = + + −

22 2 20 0 0 01/ 2 3/ 2( ) ( )A D K A D K A Aπ π− +→ + → = +measure:

Isospindecomposition

2 203/ 2( ) 3A D K Aπ+ +→ =

:extractmeasure: :extract

find:

0D K π− +→

0 0 0D K π→0D K π+ +→

is onlyschematic

Beijing 8/05 Charm L1 Ian Shipsey 38

New measurement of Λc+ Mass

hep-ex/0507009 232 fb—1

Sub. to PRD

New Result:2286.46 ± 0.14 MeVusing 4627+264 events

Shift from PDG:2284.9 ± 0.6 MeVNot measured since 1991!Best previous CLEOII, 1134 events (6 modes)

Currently charm meson masses known to 0.5 MeV (dM/M= 0.25%) Measure modes w/ large daughter mass:

Λc+ ⇒ Λ KSK+ & Σ0 KSK+

Low Q: 178 & 101 MeV Λ KSK+

Σ0 KSK+

---- = PDG

Inv. Mass

(Minimizes bias in track momentum measurement)

Beijing 8/05 Charm L1 Ian Shipsey 39

Status of Absolute Charm Branching RatiosBrτ

= ΓMeasured very precisely

Poorly knownMode PDG04 (%) Error (%)

D+ µν 100

D0 45Ds

+ µν 0.60 ±0.14 24

2.46.52526

1.7

Do K-π+ 3.80±0.09D+ K-π+ π+ 9.2±0.6Ds

+ φπ+ 3.6±0.9Λc pK-π+ 5.0±1.3

J/ψ µ+µ− 5.88 ±0.10

Key hadronic charm decay modes used to normalizeB physics

#X Observed( )efficiency x #D's produced

Br D X→ = #D’s producedis not well known.

0.170.050.08+

−

eπ ν− + 0.230.110.39 .04+

− ±

Charm produced at B Factories/Tevatron or at dedicated FT experiments allows relative rate measurements but absolute rate measurements are hard because backgrounds are sizeable & because # D’s produced is not well known.

Backgrounds are large.

|fD|2

νλ

|VCKM|2

|f(q2)|2|VCKM|2

(In early 2004)

Beijing 8/05 Charm L1 Ian Shipsey 40

(PDG) Measurement of B(Do→ K-π+)(Dominated by Y(4S) & Z0)

• Method: • Detect D*+→π+Do, Do →K-π+

compare to:D*+→π+Do, Do → unobserved

• Problem: Systematic error due to background extrapolation

B (%) Error(%) Source3.82±0.07±0.1 3.6 CLEO3.82±0.09±0.1 3.8 ALEPH3.83±0.09 2.3 PDG

α is Ρbetweenthrust axis& slow π+

(4 of 8 intervals shown)

(CLEO & ALEPHUse same technique)

(Thrust is a measureof the direction of theprimary quark pair in the event)

* 0 ~ 6D D Q MeVπ+ +→

Beijing 8/05 Charm L1 Ian Shipsey 41

(PDG) B(D+→Κ-π+π+) Y(4S) &ψ(3770)

• Method (CLEO): Measure:

B (%) Error(%) Source9.3±0.6±0.8 10.8 CLEO9.1±1.3±0.4 14.9 MKIII

9.1±0.7 7.7 PDGFrom 9.6 pb-1 (1984)

0 0*

* 0

( )( ( ))

( )B D BDB D D

DD K

KB π π

π ππ

+

+ − + +

−

+ +

++→→ →

→

(this bootstrap method can never yield a measurement of B(D+ →K-π+ π+) more accurate than B(Do →K-π+)•Method (MKIII): ψ′′→D+D- full reconstruction, limited by size of data sample

Assume this ratio is of Strong decays is given by isospin symmetry

The determination of B(D+→φπ+), which had a 25 % error also bootstraps on B(Do →K-π+).

Beijing 8/05 Charm L1 Ian Shipsey 42

Recall: the D hadronic scale sets the B hadronic scalebecause B D ~100%, All D hadronic BRs based on D Kpi a himeasurement. This is potentially a “house of cards”

Can we do better?

Beijing 8/05 Charm L1 Ian Shipsey 43

0, ,, S

K KK K

π π π

π π π π π

+ − + −

+ − + − + −

0B D∗

0D

SD∗

( )SD

π −

γ

• Ds+ from Ds

*+ → Ds+γ is not reconstructed

• Pair D*- (→ D0 π-) & γ , assume from B0→ Ds*+D∗−

This result independent of B(Ds

+→ φπ+) :

B(B0→ Ds*+D*-) = (1.88 ± 0.09(stat) ± 0.17(syst) )%

Data sample:124 million B pairs

Signal: 7488 ± 342

* *2 2( ) ( )miss beam BD D

m E E E p p pγ γ= − − − + +

New Measurement of B(Ds+→ φ π+)

• Ds+→ φ (→K+K−) π+ fully reconstructed

B(Ds+→ φ π+) = (4.81 ± 0.52(stat) ±0.38(syst))%

B (B0 → Ds*+ D*−) x B (Ds

+→ φ π+) = (8.81± 0.86(stat)) x10-4

Divide by (A)

Β0 → Ds*+ D*− : partial reconstruction1:

2:

(A)

B(Ds+→ φ π+) = (3.6 ± 0.9)% (PDG)

*2 2

*( )s

ES beam D Dm E p p= − +

uuur uuur

Signal 247 ±19

Β0 → Ds*+ D*− : full reconstruction

Recoil mass

CLEO Similar Partial recons. Β0 → Ds*+ D*−

0( ) / ( )sD D Kφπ π+ − +Γ → Γ →

HepHep--ex/0502041ex/0502041PRD 71 091104 (2005)PRD 71 091104 (2005)

13% total error (7.5%) syst

(25%)

BIG improvement!

Beijing 8/05 Charm L1 Ian Shipsey 44

e+ e−

0D

0D

K+

π−

e+

e-

#X Observed( )efficiency x #D's produced

Br D X→ =

Where the # of D’s producedis the # of tags

tag

X

ψ(3770) → DD

Can we do better? Recall:Absolute Charm Branching

Ratios at Threshold

Beijing 8/05 Charm L1 Ian Shipsey 45

D & Do +

D+s

c+

Unique Opportunities at Charm Thresholds

• Unique event properties– Only DD not DDx produced– Can get DoDo, D+D-, DsDs ,

ΛcΛc– Probably other charmed

baryons as well (not yet measured)

• Large cross sections

σ(Ds Ds) ~ 0.5 nb

R (units of σ(µ+µ−))-+

σ(µ+µ−)= 5.4 nb at 4 GeV

ψ(3770) → DD √s ~4140 → DsDs

Beijing 8/05 Charm L1 Ian Shipsey 46

31

-1

CESR CESR-c: 12 wigglers (damping at low E) 9/03-3/04 6 wiggler Pilot Run L=4.6 10 (as expected)Continue pilot run 9/03-4/05 x4 ended April '05281 pb (3770) ( 30 MarkIII, 15 BESII) 3 year CLE

at ψ

→

×

× ×

-1

-1s s

O-c program started April 2005

Year 1 goal: 3 fb @ (3770) ( ) ( 10increase)

Year 2 goal: 3 fb @ ~ 4140 MeV D D threshold ( 130 BES)Year 3 goal: 1 billion J/ ( 20 BES)

DDψ

ψ

×

××

Minor modifications:replaced silicon with 6 layerlow mass inner drift chamber summer ’03. + B 1.5T→1.0T

CLEO III Detector CLEO-c Detector

CESR (10 GeV)CESR-c (3-4GeV)

CESR-c/CLEO-c Runplan & Status

Beijing 8/05 Charm L1 Ian Shipsey 47

BEPCII/BESIII Project Design• Two ring machine• 93 bunches each• Luminosity

1033 cm-2 s-1 @1.89GeV 6× 1032 cm-2 s-1 @1.55GeV 6× 1032 cm-2 s-1 @ 2.1GeV

• New BESIII

Status and Schedule• Most contracts signed• Linac installed 2004• Ring installed 2005• BESIII in place 2006• Commissioning

BEPCII/BESIIIbeginning of 2007

X5 CESR-c designX15 CESR-c currentperformance

Beijing 8/05 Charm L1 Ian Shipsey 48

ψ(3770) Analysis Technique

• Common to all analyses, fully reconstruct 1D “the tag” thenanalyze decay of 2nd D to extract exclusive or inclusive properties

Unique to charm: high tagging efficiency:~22% of all D’s produced are reconstructed.

Compared to <1% of B’s at the Y(4S)

CLEO-c DATA

281 pb-1 ~ 1.8 million DD pairs

e+

Dsig

e−

D tagπ −

K +

π −

π +

π +

K −

Tagging creates a single D beam of known 4-momentum

(3770),

DD K

DD K

ψ

ππ ππ

+

+ − + +

−

− + − −→

→

→

Pure DD, no additional particles (ED = Ebeam).Low multiplicity ~ 5-6 charged particles/eventGood coverage: ν reconstruction Pure JPC = 1- - (mixing, CP, strong phase)

e+e- ψ(3770) DD

Beijing 8/05 Charm L1 Ian Shipsey 49

Absolute Charm Branching Ratios at Threshold

# ( )Observed in tagged events( )detection efficiency for ( ) #D tags

KB D KK

π ππ ππ π

+ − −− + − −

+ − −→ =•

Independent ofIndependent ofL and cross L and cross sectionsection

Single tags

D candidate mass (GeV)

Double tags

D K π π+ − + +→,

DD K

K π

π

π

π+

− +

− +

−

+

−→

→

2 2| |BC beam DM E p= −

D candidate mass (GeV)

Dbeam EEE −=∆Kinematics analogous to Υ(4S) BB: identify D with

σ(MBC) ~ 1.3 MeV, x2 with π0

σ(∆E) ~ 7—10 MeV, x2 with π0

:D beamE E⇒

15120±180377±20

: 10 /D beam bc bcE E M Mδ⇒ × ↓

Beijing 8/05 Charm L1 Ian Shipsey 50

(log scale)!

2484±51(combined)

1650±42(combined)

6 D+ Modes6 D+ Modes3 D0 Modes3 D0 Modes

Single tags Double tags

Signal shape: ψ(3770) line shape, ISR, beam energy spread & momentum resolution, Bgkd: ARGUS

Global fit pioneered by Mark IIINDD & Bi’s extracted from single and double tag yields with χ2 minimization technique.

D0D0

D+D+

i i iDDN N B ε= ijjiDDij BBNN ε=

ij ji

j ij

i j ijDD

ij i j

NB

N

N NN

N

εε

εε ε

=

=

Beijing 8/05 Charm L1 Ian Shipsey 51

Stat. errors:~2.0% neutral, ~2.5% chargedσ(systematic)~ σ(statistical).

ε syst. dominatesMany systematics evaluated using data, so will shrink as √L

0.0140.0060 0

( ) 0.776 0.024( )e e D De e D D

σσ

+ − + −+−+ −

→= ±

→0.170.08( DD) =(6.39 0.10 )nbσ +

−±

D0 ModesD+ Modes

Normalized to PDG

six modes more precise than PDG.

To bepublishedin PRLhep-ex/0504003

55.8/pbwill updateby 11/05

Beijing 8/05 Charm L1 Ian Shipsey 52

Comparison with PDG 2004B (%) Error(%) Source

3.82±0.07±0.1 3.6 CLEO3.82±0.09±0.1 3.8 ALEPH3.80 ±0.09 2.4 PDG

3.91±0.08 ±0.09 3.1 CLEO-c

CLEO & ALEPHD*+→π+Do, Do →K-π+

compare to:D*+→π+Do, Do → unobserved(Q~6MeV)

THEN:

NOW:

Do →K-π+

CLEO-c as precise as anyprevious measurement

π+

thrust α

CLEO-c

Beijing 8/05 Charm L1 Ian Shipsey 53

1

0

Decay / (%)2004 1

2.4 3.1 0.5( )(1.3)7.7 3.9 0.6( )(1.5)

12.5% ( ) 3.2S

B BPDG CLEO fb

D K stat sysD K stat sysD BABAR

δ

π

π π

φπ

−

− +

+ − + +

+

→

→

→ − −

CLEO-c goal is 3/fb

CLEO-c & BES III set absolute scale for all heavy quark measurements

Submitted to PRL

B (%) Error(%) Source9.3±0.6±0.8 10.8 CLEO9.1±1.3±0.4 14.9 MKIII9.1±0.7 7.7 PDG9.52 ±0.25±0.27 3.9 CLEO-c

0 0*

* 0

( )( ( ))

( )B D BDB D D

DD K

KB π π

π ππ

+

+ − + +

−

+ +

++→→ →

→

Method (CLEO) Bootstrap:Measure:

THEN:

Assume isospin

NOW:

B(D+→Κ-π+π+)

Conclusion: the charm hadronicscale we have been using for last 10 years is approximately correct

-1

-1

(BB) tag Ldt=500fb#B tags @B Factory ~ 1#D tags @Charm actory (DD) tag Ldt=3fbF

σ ε

σ ε= ∫

∫

Mostprecise

See Ecklund Radcorr, UCSD 3/05

Beijing 8/05 Charm L1 Ian Shipsey 54

Leptonic Decays Decay Constants

M

+++ BDD s ,,

Q

q

QqV

*W

+λ

λυ

2 2 2Wq m M= =

Fixed

(PseudoscalarMeson)

the meson decay constant ƒMmeasures the probability for the Q and q to have zero separation the annihilation probability is ∝ to wave function overlap

50 ( , ) (1 ) ( , )2F

QqGM V J M u k v p sµ

µ σ γ γ= −

50 ( ) Mq Q P p if pµ µγ γ =

22 12 (0)Mf ∝ Ψ

22 12 (0)Mf M = Ψ(For a meson with two heavy quarks) (Rosner)

22 22 2 22( ) 1

8F

Qq qQ MG mM V f Mm

Mν

π− ⎛ ⎞

Γ → = −⎜ ⎟⎝ ⎠

lll

This possibly repeats Jeff Richman’s lecture

Beijing 8/05 Charm L1 Ian Shipsey 55

b c

u u

u

dW −

fπ

b

d b

dt

tW WBf Bf

τ −

u

,d sW −

Mf

vτ

γMf

q

q

M e+

e−

Decay constants are important in many processes

M

+++ BDD s ,,

Q

q

QqV

*W

+λ

λυ

This possibly repeats Jeff Richman’s lecture

Beijing 8/05 Charm L1 Ian Shipsey 56

22 22 2 22( ) 1

8F

Qq qQ MG mM V f Mm

Mν

π− ⎛ ⎞

Γ → = −⎜ ⎟⎝ ⎠

lll

Decay is forbidden as ml 0 Helicity suppression

M+λ λυ

0=J

M+λ λυ

0=J

Γ(π + → e+νe )Γ(π + → µ+νµ)

≈10−4

5

( ) : ( ) : ( )

10 :1:10s e s sD e D Dµ τν µ ν τ ν+ + + + + +

−

Γ → Γ → Γ →

≈

Γ(D+ → +ν ) ∝ |Vcd |2 ≈ (0.22)2

Γ(Ds+ → +ν ) ∝ |Vcs |2 ≈ (0.97)2

Γ(B+ → +ν ) ∝ |Vub |2 ≈ (0.003)2 This possibly repeats Jeff Richman’s lecture

Beijing 8/05 Charm L1 Ian Shipsey 57

B(eν) B(µν) B(τν) D+ 8.2 x 10-9 4.2 x 10-4 1.1 x 10-3 Ds

t 7.5 x 10-8 5.7 x 10-3 5.5 x 10-2 B+ 7.5 x 10-12 3.2 x 10-7 7.1 x 10-5

π+ 1.2 x 10-4 99.99% K+ 1.6 x 10-5 63.5%

Page 58 Estimate of the leptonic Br’s using fBs = fBs=200 MeVfDs = 260 MeV, fD = 220 MeV

At first sight it is remarkable that : B(Ds+ → µ+νµ) = ( )B K µµ ν+ +→

While (ƒM2 M ) → constant

Γ(total) ∝ Μ5 so leptonic branching ratio becomes smaller as M↑If we compare ratesinstead of branching ratios:The leptonic rate is higher for the DS than for the K+

Γ(K + → µ+νµ ) = 5.13×107 s−1

Γ(Ds+ → µ+νµ ) = 6.9 ×109 s−1

Γ(Ds+ → τ +νµ) = 6.6 ×1010s−1

This possibly repeats Jeff Richman’s lecture

Beijing 8/05 Charm L1 Ian Shipsey 58

B(D+→lν)/ τD+ : fD+2|Vcd|2

B(DS →lν)/ τDs : fDs2 |Vcs|2

* Charm meson lifetimes known 0.3-2%* 3 generation unitarityVcs, (Vcd) known to 0.1% (1.1%) fD+ fDs

D meson Decay Constants

222

222

81 ||)1()( cqD

DDFq Vf

MmmMGD

q+

+

+ −=→Γ +λ

λλ πυ

|fD|2

νλ

|VCKM|2

M+++ BDD s ,,

Q

q

QqV

*W

+λ

λυ

Both the D+ and Ds leptonic decays are targetsat charm threshold facilities

Beijing 8/05 Charm L1 Ian Shipsey 59

fD+from Absolute Br(D+ → µ+ν)

1 additional track (consistent with a muon)Compute missing mass2: peaks at 0 for signal

Tag D fully reconstructed

Mark III PRL 60, 1375 (1988)

~9pb-1 2390 tags

4

11.1 12953 119

( ) 10 MeVMkIII 7.2 290BESII 12.2 0.11 371 25

DB D fµν+ −

+− −

→ ×< <

± ±

~33pb-1

5321 tags

S=3 B=0.33

BES II hep-ex/0410050

pµ

MKIII

BESII2 2 2( ) ( )beam DtagMM E E P Pµ µ+= − − − −

uuuuur uur

MM2

Beijing 8/05 Charm L1 Ian Shipsey 60

fD+from Absolute Br(D+ → µ+ν)

2 2 2( ) ( )beam DtagMM E E P Pµ µ+= − − − −

uuuuur uur 1 track µ consistent no showersD+ → µ+νD-Hadronictag

CLEO-cProposal:

2 2MM (GeV )

0D K π+ +→

PRD 70, 112004PRD 70, 112004

MC1fb-1

X20 DATA

Beijing 8/05 Charm L1 Ian Shipsey 61

fD+from Absolute Br(D+ → µ+ν)

2 2 2( ) ( )beam DtagMM E E P Pµ µ+= − − − −

uuuuur uur 1 track µ consistent no showers

D µ ν+ +→

~57 pb-1

D+ → µ+νD-Hadronictag

8 signal candidates

0D K π+ +→

2 2MM (GeV )

CLEO-cProposal:

MC1fb-1

X20 DATA

2 2MM (GeV )

28,651 tags

PRD 70, 112004PRD 70, 112004

¼ the data collected so far

Beijing 8/05 Charm L1 Ian Shipsey 62

K+π− π− K+π− π− π0

Ksπ−

Ksπ−π0

Ksπ+π− π−

K+K− π−

15

8K

fully recon

structed D

-

From 2

81

pb-1at Ψ

(37

70

)

Preliminary

Fully reconstructed D- tagAnd now with a larger data sample

All the data collected so far

Beijing 8/05 Charm L1 Ian Shipsey 63

• MC Expectations from 1.7 fb-1, 6 x data

0 0.25 0.50

200

400

600

MM (GeV )2 2

µ ν signal+

π π + ο

τ ν, τ π ν + +

sum

peak fromK π

ο +

100

50

0

50 signal events

D+ → µ+ν from CLEO-c Data281 pb-1 at ψ(3770)

D+→π+K0

D+→µ+ν

MM (GeV )

Num

ber

of E

vent

s/0.

01 G

eV2

2 2

-0.05 0 0.05

5

10

15

0 0.25 0.50

20

40

60

80

100

120

D+→π+K0

D+→µ+ν

Preliminary

Beijing 8/05 Charm L1 Ian Shipsey 64

Expt/LQCD consistent at 45% CLNow: LQCD error ~8%CLEO-c error 8%CLEO <5% within a year

Need latest LQCD predictions to few %by summer 2006 f D+ & 2007 f Ds

-1with 3fb : to 2.3%

to 1.9% @ s ~ 4140D

Ds

f

f MeV+

Comparison to the lattice

BES III may make definitive measurements

Beijing 8/05 Charm L1 Ian Shipsey 65

Extraction of the decay constant

0.225 0.0023(KTeV)

( ) 1.040 0.007 ps (PDG)

cd usV V

Dτ +

= = ±

= ±

Beijing 8/05 Charm L1 Ian Shipsey 66

COMPARISON

0

5

10

15

20

25

30

Err

or

(%)

DfsDf

)KD(Br ππ→+

)D(Br S φπ→

)KD(Br π→0

PDG04

Compare B factories & Charm FactoriesCompare B factories & Charm Factories

CFactory3 fb-1

Statistics limited

BFactory 400 fb-1

Systematics & Background limited

%Error

New BABARMeasurement

Beijing 8/05 Charm L1 Ian Shipsey 67

2004

Precision theory + charm decay constants = large impact

Beijing 8/05 Charm L1 Ian Shipsey 68

Semileptonic Decays: formalism

Q W-

q

q Hadron

νi

Qf

lVQiQf

( )22 2 2 2D X D X X Dq p p m m E mµ µ= − = + −

2 2( ) ( ) ( )( ) ( )( )X D D X D XP P J D P f q P P f q P Pµ µ µ+ −= + + −

Nuclear β decay Vud, K→πeν VusD →Kev Vcs b →clν Vcb b →ulν Vub

•Weak current is understood. The work is in the hadronic matrix element expressed in terms of form-factors. for D→Pseudoscalar λ+ ν

•For λ = e, contribution of f−(q2)→0,

Traditional way to determine magnitudes of CKM elements

•Kinematics:

=X

The form factor measures the probability that the final state mesonwill be produced

Beijing 8/05 Charm L1 Ian Shipsey 69

The hadronic current

B

b

q

c

q

−W−l

λυ

(*)D

D

c

q

c

q

+W+l

λυ

(*)K

Beijing 8/05 Charm L1 Ian Shipsey 70

Two Key Kinematic Configurations

b

q

c

q−l v2max

2 qq =

c

q 2min

2 qq =

v

−l

c

q

s

q+l υ

2max

2 qq =

s

q 2min

2 qq =

υ

−l

υ

Form factormaximum

Form factorminimum

Beijing 8/05 Charm L1 Ian Shipsey 71

Goals for a threshold Semileptonic Decay

( )2

3

23

22 24

( )cq PV Pf

D Pdq

qd ν

π +

Γ →=

l

Contraction with leptonic current

Quark models, HQET, Lattice & other methods have all been invoked to calculate form factor absolute normalizations. These calculations have been done

mostly at q2 =0 or q2 =q2max. (i..e w=1, just like F in Vcb in B →D* lν)

For PS PS decays data is mostly at q2 =0. Need to interpolate. The q2 dependenceis intrinsically non-perturbative. Models make phenomenological guesses about the shapes of the form factors as a function of q2..

To find Vcs & Vcd need f from theory at one fixed q2 point.

The lattice calculates rates as a function of q2. Charm semileptonic decays provide a powerful test of the lattice predictions. Once validated, the lattice can be used with confidence in the extraction of CKM matrix elements in other D (& also B) semileptonic decays .

0 0.5 1 1.5 2 2.5 3

3P

2q

cleanest theory

highest rate

D lπ ν→

22 2

pole

(0)( )1 /

ff qq m

++ =

−

Beijing 8/05 Charm L1 Ian Shipsey 72

K-

π-

e+

K+

ν

Semileptonic Decays

Tagging creates a single D beam of known 4-momentum

Semileptonic decays are reconstructed with nokinematic ambiguity

Hadronic Tags: 32K D+ 60K D0

0miss missU E pº - =rss

ν+−→ eKD0

Eve

nts

/ (

10 M

eV )

(~1300 events)

U = Emiss– |Pmiss| (GeV)

D+ results are new, D0 update ICHEP

Accepted for Publication in PRLAugust 12 2005Hepex/0506053 &0506052

CLEO-c 1/5 data

0

0

0

0

(3770)

,

D

D

D

D K eK π

ψ

ν+ − − +→ →

→

Beijing 8/05 Charm L1 Ian Shipsey 73

More Cabibbo allowed modes

0 *

* 0 D K e

K Knp

- +

- -

®®

U = Emiss– |Pmiss| (GeV)

Eve

nts

/ (

10 M

eV )

Eve

nts

/ (

10 M

eV )

Eve

nts

/ (

10 M

eV )

Eve

nts

/ (

10 M

eV )

ν++ → eKD 0

(~550 events)

U = Emiss– |Pmiss| (GeV)

U = Emiss– |Pmiss| (GeV)

c s Cabibbo Favored 57 pb-1 Data

(~90 events)

*0

*0

D K e

K K

n

p

+ +

- +

®

®

(~420 events)

Historically Cabibbo allowed modes: provide a significantbackground to Cabibbosuppressed modes, makingthe latter particularlychallenging…..

Beijing 8/05 Charm L1 Ian Shipsey 74

Cabibbo suppressed modes0D eπ ν− +→

0D eπ ν− +→

U = Emiss– |Pmiss| (GeV)

Eve

nts

/ (

10 M

eV )

(~110 events)

Eve

nts

/ (

10 M

eV ) νπ ++ → eD 0

(~65 events)

U = Emiss– |Pmiss| (GeV)

57 pb-1 Data

Compare to:state of the art measurementat 10 GeV (CLEO III)PRL 94, 11802

Note:kinematicseparation.

∆m

S/N ~40/1

S/N ~1/3

* 0

0

( ) (:

)

s

s

Tag with

obs

D D

D

m merva

mble

π

π ν

π π π

+

+ −

→

→

∆ = −

l

l l

Beijing 8/05 Charm L1 Ian Shipsey 75

*0D K e n+ +®0

*0

( )( )

D eD K e

r nn

+ +

+ +

G ®G ®

2(GeV/c )mpp

U = Emiss– |Pmiss| (GeV)

0D er n+ +®

(~30 events)

U = Emiss– |Pmiss| (GeV)

0 *D K e n- +®

(~30 events)

D ew n+ +®(8 events)

(5σ)

57 pb-1 Data

1st Observation.1st Observation.

E791 PLB 397325(1997)Relative rate:

S/N ~1/2S/N ~15/1

0D er n- +®

More Cabibbo supressed modesOnly measurementuntl now

*

( ) ( )/( ) ( )B e D eB K D Ke

r n r nn

+ +

+

G ® G ®G ® G ®l l

Useful for Grinstein’sDouble ratio Vub2/ Vcb2

Beijing 8/05 Charm L1 Ian Shipsey 76

0102030405060708090

100

1 2 3 4 5 6 7 8 9 10 11

Decay modes

Err

or

(%)

PDG

CLEO-c3fb-1%

BB

δNormalized to PDG

CLEO-c already all modes more precise than PDG.

Full CLEO-c data set (later BESIII) will make significant improvements in the precision with which each absolute charm semileptonic branching ratio is known

0

0*

0

5 :

6 :7 :

D K e

D K eD e

n

np n

+ +

+ +

+ +

®

®®

0

0

*0

8 :9 :

10 :

11 :

s

s

s

D eD K e

D K e

D e

r nn

n

f n

+ +

+

+

+

®®

®

®

0

0 *

0

0

1 :2 :3 :4 :

D K eD K eD eD e

nn

p nr n

- +

- +

- +

- +

®®®®

Preliminary Results Similar analysis by BES II

55.8/pbwill updateby 11/05

Accepted for Publication in PRLAugust 12 2005Hepex/0506053 &0506052

Beijing 8/05 Charm L1 Ian Shipsey 77

From the semileptonic measurements…

0.1)()(

0

0

=→Γ

→Γ++

+−

νν

eKDeKD

2.04.1)()(

0

0

±=→Γ

→Γ++

+−

νν

eKDeKD

0

0

0

0

( ) 1.00 0.05( ) 0.04( ) CLEO-c( )( ) 1.08 0.22( ) 0.07( ) BES-II( )

D K e stat sysD K eD K e stat sysD K e

νννν

− +

+ +

− +

+ +

Γ →= ± ±

Γ →

Γ →= ± ±

Γ →

0

( ) (15.1 0.5 0.5)%

( ) (6.1 0.2 0.2)%xcl

exclB D Xe

B D Xeν

ν

+

→ = ±

±

±

→ = ±

∑∑

Long standing puzzle in D semileptonic decays

Isospin requires

PDG gives

CLEO-c & BES IIsolve the problem

Is anything missing?sum up all the individualdecay modes

0

PDG (11%)PDG (( ) (6.87 0.28)%

( ) (17.2 1.94

)%

%.1 )

B DB D

Xe Xe+

+

+

→ =

→

±

= ±Compare to inclusive rate form PDG (not very precise)room for additional modes

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Question: what could the additional modes be?

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2q

2qdd

Γ

LQCD : shape correct:

Lattice comparison – the shape

D0→π-e+ν

22

2

2

2

~ 0.4GeV B Factoryq

~ 0.1 GeV FOCUS~ 0.025 GeV CLEO-c

qδ

Improved precision soon:The threshold advantage 1) Low background crucial forπ final state2) neutrino direction known

CLEO-c 1/5 data FOCUS all data

S/N ~40/1 S/N ~1/2.5

S/N ~6/1S/N >300/1

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Lattice comparison: the normalization If we assume that the lattice shape is OK ⇒we can use branching fraction measurements to validate the normalization

LQCD : normalization agrees with data!

Total lattice Br agrees with experiment for PDG: Vcs, Vcd

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Vcs and Vcd

• Assuming that shape and normalization of the form factors are OK:

Using isospin averaged widths

i.e. combining D0 and D+

Vcs =0.953±0.017(exp) ±0.067(th)Vcd =0.214±0.009(exp) ±0.016(th)

LQCD errors dominate expt.errors

Need 1fb-1 at ψ(3770) (soon) and LQCD to few % within 1-2 years

Artuso LP03not official CLEO-c

Expt. errors Vcs ~2%Vcd~4%

Result is theory limited

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U = Emiss - Pmiss

CLEO-c: (& BES III) PS → PS & PS → V absolute form factor magnitudes & slopes to a few%. Stringent test of theory! (Unique)

D0 →πlν

D0 →Klν πdpdΓ

(GeV/c)pπ

CLEO-cMC

Lattice QCD

πdpdΓ

D0→ πlνD0 →πlν

CLEO-cMC

(GeV/c)pπ

1fb-1

Testing the Lattice with (semi)leptonic Charm Decays

1fb-1

This is what the data will look like soon (x5 existing data)

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With 1fb-1 @ ψ(3770) Rlskexp ~3% uncertainty

10% uncertainty

With 1fb-1 @ 4140 Γ(Ds→lν) /Γ(Ds→ηlν) independent of Vcs Rlsk

exp ~ 3% uncertainty

δVcs /Vcs = 1.6% (now ~7%*) δVcd /Vcd = 1.7% (now: 5.4%)D eπ υ+→D Ke υ+→

Then Tested lattice to calc. B→πlv is available for precise exclusive Vub* 3 flavor unquenched LQCD + D Kev (last sldie) (note W decays at LEP in hadronic to leptonic 1.3%)

LatticeExperiment

Artuso LP03

Beijing 8/05 Charm L1 Ian Shipsey 84

Unitarity Tests Using Charm

2nd row: |Vcd|2 + |Vcs|2 + |Vcb|2 = 1 ??CLEO –c: improves precision (if theory D →K/πlν good to few %)& 1st column: |Vud|2 + |Vcd|2 + |Vtd|2 = 1 ?? with similarprecision to 1st row

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛=

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛

=⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛

bsd

VVV

VVVVVV

bsd

tbtstd

cbcscd

ubusud

'''

Compare ratio of long sides to 1.3%

|VubVcb*||VudVcd*|

|VusVcs*|

uc*=0

uc*

(3fb-1)

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Inclusive D0/D+ Absolute Semileptonic Branching Fractions (CLEO-c)

sc

, , 3e uµ ×, , 3ev v dµ ×

Naïve spectator model:

DD00/D/D++ lifetime difference due to hadronic width (Pauli int. DD++))

0 0( ) / ( ) ( ) / ( )D D B D e X B D e Xτ τ+ + + += → →( ) ~ 20%B D e X+→

0PDG ( ) (6.87 0.28)%PDG ( ) (17.2 1.9)%

B D e XB D e X

+

+ +

→ = ±

→ = ±

Now: precision measurements of Γ(D→Xlν) and Γ(Ds→Xlν) needed to constrain background to Vub in B inclusive semileptonic decay

But gluon emission enhances hadronic rate( ) ~ 7 %B D e X+→

Historically: B(D→Xlν) important to interpret charm lifetime hierachy

Isospin symmetry requires Γ(D+→Xlν)= Γ(D0→Xlν)

DD00 DD++

dB/B=11%dB/B=11%

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D+ → K-π+ π+

D0→K-π+

3σ 3σ3σ 3σ

Β(D→Xlν) Analysis Technique 1: Tag Modes

:identify D with

E & M

D beam

bc

E E⇒

∆

Dbeam EEE −=∆

Control regionsevaluate smallbackgrounds in Dtagging

Only golden modes+

D0→K-π+ &

D+ → K-π+ π+

Kinematics analogous to Υ(4S) BB:

2 2| |b c b ea m DM E p= −

74K D0 tags47K D+ tags

Details (probably will not discuss)

Beijing 8/05 Charm L1 Ian Shipsey 87

( )(2 )e ta g eD DY B D e X N ε ε+= →

( ) ( 2 )D ta gD DN ta g N ε=

Measure e spectrum in tagged events:

Correct for ε : Independent of L and NDD/( )( )

e e

D

YB D e XN tag

ε+→ =

Measure raw spectra / / in tagged events:16, 50 MeV bins (0.2<p<1.0 GeV) Right sign: ( / / )Wrong sign: ( ( / / )an unfolding procedure gives true populations

e K

K D D e K XK D D e K X

π

π π π

π π π

± ± ±

+ − − − + + + +

+ − − − + − − −

← →

← →

( ) ( ) ( )

e e eK

e K

Ke K

Y p A p N pe f f e

f fK f f K

π

π π π

π

επ ε π

ε

=

⎛ ⎞ ⎛ ⎞⎛ ⎞⎜ ⎟ ⎜ ⎟⎜ ⎟=⎜ ⎟ ⎜ ⎟⎜ ⎟⎜ ⎟ ⎜ ⎟⎜ ⎟⎝ ⎠ ⎝ ⎠⎝ ⎠

is probabilty a is identified as an e are efficiencies including PIDef π π

ε

+

0S

& from data:

ee for e, D for K &K for low mom.

ijf

K

ε

γ π π π

ππ π

− + +→

→

Β(D→Xlν) Analysis Technique 2: Electron spectrum

Subtract charge symmetric background (wrong sign) & D background (∆E sidebands) Extrapolate to p=0 GeV

Tally number of tagsOverview

MoreDetail

Measured True

Details (probably will not discuss)

Beijing 8/05 Charm L1 Ian Shipsey 88

RS

D+ →Κ- π+π+

D-→ e-X ν

D+ →Κ- π+π+

D-→ e+X ν

WS

Electron right-sign Electron Wrong-signTag Sideband

Raw measured spectra for D+

Measures charge symmetric backgroundmostly π0 Dalitz decays & γ conversions

Measures false tag background

Similar distributionsfor D0

Right sign Wrongt sign

RS 8.3K

WS 228

RS 127

WS 10

Details (probably will not discuss)

Beijing 8/05 Charm L1 Ian Shipsey 89

Corrected Spectra & Results

D+

D0

Momentum (GeV)

DΓ(D

e+ X

ν)/DDp

(p

s-1

GeV

-1 )

0

0.1

0.2

0.3

0.2 0.4 0.6 0.8 1

0

( ) (1 5 .1 0 .5 0 .5)%

( ) (6 .1 0 .2 0 .2 )%xc l

exc lB D X e

B D X eν

ν

+

→ = ±

±

±

→ = ±

∑∑

Unfolded background subtracted efficiency corrected lab spectrum – no FSR correction

0

(2.5%)(( ) (6.45 0.17 0

) (16.19 0.2(3.5%

0 0.36)1 )%

)%. 5

B DB D Xe

Xeνν

+

→ = ± ±

→ = ± ±

Sys errors EID 2%, Hadron ID 1% FSR 1% p 0 1%

Compareto CLEO-cexcl.

Incl & excl. consistent, some room for additionalexclusive modes

-1

0

0 1

PDG (11%)PDG (4.1%)

( ) (17.2 1.9)%

(( ) (6.87 0.28)%

( )) (0.1557 0.0

(0.1572 0.0041 0.0019 0.0035)p

37)pss

0

B D e X

D eB D e X

D e XX

+ +

+ +

+

+ −

→ = ±

Γ → = ±

→ = ±

± ±

±

Γ → =NOW

THEN

Fit low p data to polynomial to extrapolate p=0,( 8% has p<200 MeV) dB/B

0

0

C L E O -c ( ) / ( ) 2 .5 1 0 .0 4P D G ( ) / ( ) 2 .5 3 0 .0 2

B D B DD Dτ τ

+

+

= ±

= ±Excellentagreement!

preliminary

’79 DELCO

600 evts

10,100evts

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Additional Slides

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CLEO-c INPUTS TO CKM ANGLE φ3 /γ

See talks by Asner, Fleischer, Grossman, Petrov CKM2005

1. Gronau-London-Wyler Method– B- →DCPK-

– Statistics Limited so far– D mixing parameters can alter γ

2. Atwood-Dunietz-Soni Method– B- →D K-

– Requires very large Ldt – CLEO-c measure rD & cos δD

3. Dalitz plot Method– B- → DK-, D→ Ksπ+π-, π+π-π0, KsK+K-

– limited by uncertainty due to Dalitz plot model– CLEO-c quantum correlated D’s reduce model dependence

Beijing 8/05 Charm L1 Ian Shipsey 92

0 0D DK

mixingπ+ −

→

→

•BFac/Tevatron: large DCSD interferes with signal unknown phase δ

(CLEO-c measures δ same for ADS)

D CP violation, mixing & rare decays sensitive to new physics at high mass scales through intermediate particles entering loops.

udsu

cu

W+

Κ-

π+ usdu

cu

W+

D0 π-

Κ+CF DCSD

CLEO-c Probes of New Physics (+ input to φ3 /γ)

Μixing: ψ(3770)→DD(C = -1) Coherence simplifies study DCSDUnmixed: D0→ K-π+ D0→ K+π-

mixing: D0→ K-π+ D0→ D0 →K-π+ (+Klv Klv)Sensitivity: 10-4 current limit: 10-3

y’= ycosδ-xsinδx’= xcosδ+ysinδ

D0

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ψ(3770)L=1 C=-1 CP anti-correlated

–cos δD ~ ±10%

CLEO-c Measurement of Strong Phase

Dr

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•CP violating asymmetries•Unique:L=1,C=-1 CP tag one side, opposite side same CP• CP=±1 ← ψ(3770) → CP=±1 = CPV Sensitivity (two body final states) Acp < 0.01•CP tagging allows many searches for CPV in Dalitz plots sensitive to amplitudes

Rare charm decays. Sensitivity: 10-6

CLEO-c Probes of New Physics (+ input to φ3 /γ)

2. Dalitz plot Method– B- → DK-, D→ Ksπ+π-

– limited by uncertainty due to Dalitz plot model currently 10-110

– CLEO-c CP tagged D’s reduce Dalitz plot model dependence, compare CP+ DD Ksπ+π-,CP- DD Ksπ+π-, & untagged D Ksπ+π-,Extrapolation of Belle study CLEO-c 285 pb-1/6fb-1

(3770 + DsDs) reduce model error to ~70, ~10

CLEO-c

D Ksπ+π-

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Theoretical errorsdominatewidth ofbands

2004

Today: the potential of quark flavor physics to discover new physics is limited by theory errors

precision QCD calculationstested with precision charmdata from CLEO-c

theory errors of afew % on B system decay constants & semileptonicform factors

+500 fb-1 @ BABAR/Belle

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2004

precision QCD calculationstested with precision charmdata from CLEO-c

theory errors of afew % on B system decay constants & semileptonicform factors

500 fb-1 @ BABAR/Belle

Precision theory + charm = dramatic increase in the potential of quark flavor physics to discover new physics

+

Theoretical errorsdominatewidth ofbands

Plot usesVub, Vcbfrom exclusivedecays only

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Charm at CDF

The hadronic B trigger a major milestone~150 VME boards find and fit tracks in Silicon, offline accuracy in a 15µs pipeline

Secondary vertex level 2 trigger|D|> 100 µm (2 body)

Summer 2002

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Differential Semileptonic Rates P Pev

D0→K-e+ν D0→π-e+ν

2 2 2cs,d2 |V | |f (q )|

qdd +

Γ∝

Raw q2 No efficiency correction. Results by summer hoped for

2qdd

Γ

2q

CLEO PRL 94/, 11802

(PRL 94, 011601 (2005)

STATUS2005 (CLEO IIIFOCUS BES II)

LQCD : shape & rate correct: precision~10%

22

2

2

~ 0.4GeV CLEO q

~ 0.025 GeV CLEO-c

qδ

(1) No kinematic ambiguity (2) rest frame of D q2 resolution x 16 better

πeν

Keν

CLEO-c

2

ddq

Γ

shaperate

First unquenched LQCD for D→π/K e ν

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Lattice

There is remarkably little difference between the shapes of pole, modfiied pole and lattice

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Pole mass comparison, good consistency

*

1.93 0.05 0.031.89 0.05 0.0351.91 0.04

( ) 2.12s

Expt pole massFOCUSCLEO IIIWorld Avgm D

± ±± ±± 5.1 σ below the spectroscopic mass

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Differential Semileptonic Rates P Vev

CLEO-c*0

*0

D K e

K K

n

p

+ +

- +

®

®

Preliminary, first lookat the data, also D ρeνno results at this time

The J=1 vector particle results in more complicated decay angular distributions

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Theory & CharmSpectator model,

All lifetimes equal Factor of ~15x spread in lifetimes (0.3 for beauty)Large final-state interactions in charm

OPEs, lifetimes qualitative

HQET: Useful for spectroscopy, but larger (1/m)N corrections,

& no heavy-to-heavy decays like b ⇒ c l ν

Lattice QCD:Useful for charm & bottom

(but charmonia more relativistic…)Good opportunities to test in charm sector ( c.f. CLEO-c BESIII program )Only approach that is systematically improvable & testable to a few %

B vs. D decay & Penguin example:B decay: integrate out top ⇒ local 4-quark operator D decay: dominant strange light ⇒ not short-distance!

Will concentrate on the lattice in this lecture

Beijing 8/05 Charm L1 Ian Shipsey 105

SummaryCLEO-c 1st data (6 wigglers) summer 2004, updated + new results today.Detector performing well, data is excellent & is well understood.fD+ is now known to 22% (was 100%) D0→π-e+ν now 14% (was 45%) 1st observations: D0 →ρ e+ν, D+ →ω e+νMost precise measurements of D+ →K-π+ π+

x4 data by April. Three year program starts 4/05several % precision in all key charm quantities, + probe for new physics & glueballs

Lattice goal to calculate in D,B,Y,ψ to 5% in a few years and a few % longer term CLEO-c about to provide few % tests of lattice calculations (& other QCD techniques)in D system & in onia, quantifying the accuracy for application of LQCD to the B system

BABAR/Belle/CDF/D0 (later LHC-b/ATLAS/CMS SuperKEKb) + theorycan reach few % precision for Vtd, Vts, γ and exclusive Vub,Vcb.

CLEO-c maximizes the sensitivity of the worldwide heavy quark flavor physics program to new physics this decade and paves the way for understanding beyond the Standard Model physics at the LHC/LC in the next decade(s).

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The importance of precisionabsolute Charm BRs IV

b →bb

-b c +cud+ccsν→ l

QCD prediction:(Neubert & Sachrajda, Nucl. Phys. B483,339 1997)

(Plot from Parodi at HF9)

areanti-correlatedSL cBR n

Theory can accommodate present values butexperimental errors are large test becomesmore incisive if abs charm BR’s were known precisely

As a function of the effective charm quark mass & scaleat which QCD corrections are evaluated

( ), is low compared to theory A possible explanation is that the c quark effective mass is low large decay rate for b ( )

( )is negatively correlated to The simultaneous mea

SL

c c c SL

BR B b cccs d

n n n Br

ν= →

→ →→ = +

l

csurement of and n can clarify the theoretical pictureSLBr

To measure nc need absolute charm Br’s

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Belle predict excellent q2 resolution and low bkgd result expected soon

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Charm vs. Beautyλ = sinθC ~ 0.22 Cabibbo quark-mixing angle

Decay rate: O(1) O(λ4)“Cabibbo”-suppression of b decay compensates Γ ~ m5 behaviorLong B life inspired Wolfenstein’s famous CKM parameterization…Advent of silicon revolutionizes b physics, as well as c

Mixing Ampl. : O(λ2) O(λ6) x f( mt )Charm decays too fast to mixB mixing enhanced by top mass ( actually, Bs enhanced too much! )

Fully Reconstruct: 20% < 0.1%At factories producing meson pairs: Can use full-recon. “Tag”:Study rest of event after full reconstruction of one hadronic decay-- get direction of other meson-- lower background (less combinatorics, reject continuum)

Similar numbers of single tags for charm & beauty, but:-- useful # of Double Tags (reconstruct both D’s) for charm !

since NDouble ~ (εB)2 : MUCH smaller for B’s than D’s

Very different but intimately linked

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Christine Davies EPS2005