D-meson results from CLEO• “Rumors of my death are exaggerated”.

– 2003: CLEO re-incarnated (phoenix-like) into 3-4 GeV electron-positron collider.

– First “CLEO-class” detector at charmonium energies

– Continuing nearly 30 year physics program• Longevity>U2 (but <Rolling Stones)

– Scheduled to take data into 2008; expect active physics analysis program for additional five yrs.

• Focus here on updated D+ (2005 pub.) plus recent results on semileptonic+hadronic D modes.

• THANKS TO DAVID ASNER, WERNER SUN AND ALEX SMITH, FROM WHOM I SHAMELESSLY LIFTED SLIDES WHOLESALE!

CLEO-c Detector/CESR-c Accelerator

SVX

CLEO III • Ability to run at cms energies from J/ up to (5S)

Beam Energy (GeV)

CLEO-III

SVXMini DriftChamber

CLEO-c

(3770)

’

Simple conversion of detector from (4S) to (3770) running; CESR reconfiguration now prohibits return to Upsilon system.

Silow-mass tracking

Running at the (3770)

• No extra energy for fragmentation particles– Known/coherent initial state – Clean neutrino reconstruction– Simple combinatorics

• Large cross section• Good kinematic particle ID

Ecm ~ (3770) Ecm ~ (4S)

CLEO III CLEO-c

Overview of D-tagging techniques• ee (3770) DD• Kinematics analogous to (4S)BB: (MBC) ~ 1.3

MeV, x2 with 0

(E) ~ 7—10 MeV, x2 with 0

• Single tag (ST): ni = NDDBii

• Double tag (DT) : nij = NDDBiBjij

– Ratio + algebra allows extraction of BR; eff cancels to 1st order

• Take advantage of low multiplicity, low backgrounds.

K not found (MC)

K found (MC)

Example: K eff from

D0 K+

≈ 91%

DK

D

DKXX

MM allows extraction of efficiency from data! (Same tracking eff technique in earlier CLEO-II DKpi analysis)

Leptonic Decays: D+→μ+ν

2

2222 2

218

lFl cdD D

D

mGD l f m M V

M

Compare with lattice QCD predictions!

fD+ from Absolute Br(D+ )

1 additional track ()Compute missing mass2: peaks at 0 for signal

Tag D fully reconstructed

Mark III PRL 60, 1375 (1988)

~9 pb-1 2390 tags

4

11.1 12953 119

( ) 10 MeV

MkIII 7.2 290

BESII 12.2 0.11 371 25

DB D f

~33pb-1

5321 tags

BESII Phys.Lett.B610:183-191, (2005)

D Leptonic Decays: D++

• Many large BR tag modes– ~25% efficiency for reconstructing a

tag• Signal is very pure after tagging• Roughly 30x BES sample• (281/pb)

Getting the ABSOLUTE branching fractions... “Other side D” tag

e+ e-

Signal D+

Tag D

• Tag D decay modes:–

00

0

0

0

S

S

S

KD

KD

KD

KD

KD

22beam

2MM ppEED

• Fit for (“missing mass”)2:

TAG SAMPLE

Compare with previous results & Lattice Calcs

Since fD measures w.f. overlap at origin, expect comparable (slightly smaller than) fDs

222.6(16.7)(3.4)

Phys.Rev.Lett. 95 (2005) 251801

Semileptonic Decays

c

e+

e

W+

, s d

,u d

|Vcs| , |Vcd|

,u d Test LQCD on shape of f+(q2) Use tested Lattice for norm. Extract |Vcd|

Extract B(DXe)

D FF related to B FF by HQS Precise D FF’s can lead to reduced theory in |Vub| at B factories

Same holds for DVl, except 3 FF’s enter

223

322

24qf

pVGPlD

cqF

Exclusive Semileptonic D Meson Decays

)()(

)()( 0

00

DNeK

eKNeKDB

• Reconstruct one D meson in hadronic tagging channel– –

• Reconstruct the remaining observable tracks

• Use the missing energy (Emiss) and missing momentum (|Pmiss|) in the event to form kinematic fit variable for the neutrino

Technique:

22candidatebeambc PEM

candidatebeam EEE

missPEU

miss

From fit of Mbc

and E for number of tags

Signal componentfrom fit to variable U

From MonteCarlo/Data

))()(()(

)()(0

00

DNDNeK

eKNeKNB

Both flavors combined:

K-

-

e+

K+

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

eKD0

Events

/ (

10

MeV

)(~1300 events)

U = Emiss– |Pmiss| (GeV)

D+ semileptonic results (including omega!)

D0 semileptonic results – note wrt PDG

Compare CLEO-c to PDG 2004

MBC (log scale) for ST modes: D+D

Double Tag Analysis gives Had BR’s

Mode ND (103) ND (103) D(%)

K 5.11±0.07 5.15±0.07 65.1±0.2

K 9.51±0.11 9.47±0.11 31.6±0.1

K 7.44±0.09 7.43±0.09 43.8±0.1

K 7.56±0.09 7.56±0.09 51.0±0.1

K 2.45±0.07 2.39±0.07 25.7±0.1

K0s 1.10±0.04 1.13±0.04 45.7±0.3

K0s 2.59±0.07 2.50±0.07 22.4±0.1

K0s 1.63±0.06 1.58±0.06 31.2±0.1

KK 0.64±0.03 0.61±0.03 41.1±0.4

All D0 DT

2484±51

All D+ DT1650±42

Double Tag Analysis: Fit Results• Fit includes both statistical and

systematic errors (with correlations) [arXiv:physics/0503050].

• Precision comparable to PDG WA.

(systematic) ~ (statistical).

– Many systematics measured in data, will improve w/time.

• Simulation includes FSR, so we measure B (final state + n).

– Using efficiencies without FSR correction would lower B.

• NDD includes continuum and resonant production.

Parameter ValuenoFS

RNDD (2.01±0.04±0.02)x105 -0.2%

B(K+) (3.91±0.08±0.09)% -2.0%

B(K+) (14.9±0.3±0.5)% -0.8%

B(K++) (8.3±0.2±0.3)% -1.7%

ND+D- (1.56±0.04±0.01)x105 -0.2%

B(K++) (9.5±0.2±0.3)% -2.2%

B(K++0) (6.0±0.2±0.2)% -0.6%

B(KS+) (1.55±0.05±0.06)% -1.8%

B(K0S+0) (7.2±0.2±0.4)% -0.8%

B(K0S+-+) (3.2±0.1±0.2)% -1.4%

B(K+K+) (0.97±0.04±0.04)% -0.9%

(D0D0) (3.60±0.07+0.07-0.05) nb -0.2%

(D+D-) (2.79±0.07+0.10-0.04) nb -0.2%

(+-)/(00) 0.776±0.024+0.014-0.008 +0.0%

Comparison with PDG 2004

• Measurements and errors normalized to PDG.• PDG global fit includes ratios to K-+ or K-++.• No FSR corrections in PDG measurements.• Our measurements also correlated (statistics and

efficiency systematics).

B(D

0 K-

+)B

(D+ K

- +

+)

Other direct meas.

Overall C.L

25.9%

MBC distributions

in E signal regionand E sidebands

D → n(+) m(0)• Study Cabibbo-suppressed D

decays with single tags only.– Double tag technique not as

profitable—statistics too low.– Normalize Bs to ref. modes.

• MC tuned to match mass spectra in data.

• Bkgnd from Cabibbo-favored decays with K0

S → +-, 00.– Veto M() near K0

S mass.

D0

D+

M(+-)

M(00)

Reference

modes

X-checked with search including

What’s coming?• Results on CP-modes,

• Dalitz analyses & rare decay modes,

• Via scan, have found “optimal” run energy for production of Ds mesons…beginning to accumulate tag sample; apply D-reconstruction machinery to Ds,

• Immediate Ds goals: high-precision msrmnt of normalizing mode ( semileptonic modes (CF and CS), rare modes “tailored” for threshold msmrnts (p-nbar, e.g.)

Tags Invariant Masses from the 4160 & the 4180 MeV DATA

23316 15018 9719 30422

22753 7010 82155615

Total # of Tags = 1219 ± 67(stat)

s K* K-

Impact of CLEO-c Measurements

• Calibration and validation of Lattice QCD• Test theoretical form factor calcs. and models

– Impacts prediction of form factors for B meson decays

• Measurements of |Vcs| and |Vcd|• Improved decay constants fB possible from CLEO-c fD measurement + LQCD

• Improved measurement of many important normalization modes

e+

W+

ElectroweakPhysics

StrongPhysics

CLEO-c Impact on Unitarity Triangle

Now: Theory uncertainties dominate

With few % theory errors

made possible by CLEO-c and 500

fb-1 each from the B factories:

CLEO-c + Lattice QCD +B factories + ppbar

CLEO-c + Lattice QCD +B factories

CLEO-c

Future of Precision Flavor Physics

Vub/Vub~155%lB

l

D

Vcd/Vcd~71.1%lD

Vcs/Vcs~161.4%

l

B D

Vcb/Vcb~53%

Bd Bd

Vtd/Vtd~365%

Bs Bs

Vts/Vts~395% Vtb/Vtb~29%

Vus/Vus~1%

l Vud/Vud~0.1%

e

pn

t

b

W

Goal: Measure all CKM matrix elements and associated phases in order to over-constrain the unitary triangles