Recent Charm from CLEORecent Charm from CLEO

Yongsheng GaoSouthern Methodist University

(CLEO Collaboration)

HEP2003 Europhysics ConferenceHEP2003 Europhysics Conference Aachen, GermanyAachen, Germany

July 17 ─ 23, 2003July 17 ─ 23, 2003

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Outline Outline

IntroductionIntroduction

Rare Charm Results from CLEORare Charm Results from CLEO D+ +, K+, K+Ks

D0 +0 Dalitz Analysis

First Observation of D0 Ks

First Search for D0

Future Outlook and CLEO-cFuture Outlook and CLEO-c

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Why Rare Charm?Why Rare Charm?

Hunting Ground for New PhysicsHunting Ground for New Physics– Possible New Physics in box & loop– SM background suppressed – Precision measurements possible– Clean samples already exist!

D0D0E79E7911

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Charm Physics at CLEOCharm Physics at CLEO

> 360 Publications since 1980 Diverse physics topics Over 30% on Charm Physics

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CLEO DetectorCLEO Detector

CLEO II (1989 – 1995):CLEO II (1989 – 1995): 4.7 fb-1

CLEO II.V (1995 – 1999):CLEO II.V (1995 – 1999): 9.0 fb-1

CLEO III (1999 – 2002):CLEO III (1999 – 2002): 16.0 fb-1

CLEO-c (2003 – 2008): > 7 CLEO-c (2003 – 2008): > 7 fb-1

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DD++ ++, K, K++, K, K++KKss

Study SU(3) Symmetry BreakingStudy SU(3) Symmetry Breaking

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DD++ ++, K, K++, K, K++KKss

First First StudyStudy

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DD++ ++, K, K++, K, K++KKss

** Preliminary **** Preliminary **

CLEO CONF 03-02CLEO CONF 03-02

hep-ex/0306019hep-ex/0306019

=1 in the limit of SU(3)=1 in the limit of SU(3)

>1>1 indicates destructive interference indicates destructive interferenceBetween internal & external Between internal & external

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E791 E791 DD++ --+ + Results Results

Fit Frac. (%) Fit Frac. (%)

20.8 ± 2.4 33.6 ± 3.2 ± 2.2

f 7.4 ± 1.4 6.2 ± 1.3 ± 0.4

f 6.3 ± 1.9 19.4 ± 2.5 ± 0.4

f 10.7 ± 3.1 2.3 ± 1.5 ± 0.8

22.6 ±3.7 0.7 ± 0.7 ± 0.3

Non-res 38.6± 9.7 7.8 ± 6.0 ± 2.7

46.3 ± 9.0 ± 2.1

138/162

Phys. Rev. Lett. 86: 770, 2001

Strong Evidence for Strong Evidence for σσ (500) (500)

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Dalitz Analysis of Dalitz Analysis of DD00--++00

m2() (GeV2)

m2 (

) (G

eV2 )

No contribution from (500) at ~1% level

m2() (GeV2)

0 1 2 3m2() (GeV2)

0 1 2 3m2() (GeV2)

0 1 2 3

Amplitude Phase Fit Fraction

+ 1 (fixed) 0 (fixed) 76.5±1.8±4.8

0 0.56±0.02±0.07 10±3±3 23.9±1.8±4.6

0.65±0.03±0.04 4±3±4 32.3±2.1±2.2

NR 1.03±0.17±0.31 77±8±11 2.7±0.9±1.7

** Preliminary **** Preliminary **

CLEO CONF 03-03, CLEO CONF 03-03, hep-ex/0306048hep-ex/0306048

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First Observation of First Observation of DD00KKssoo

• CLEO’s KS and BaBar’s KSKK+ Dalitz analyses• KSa0(980) seen in KS,, a0(980) is dominant

05.007.038.0)(

)(00

00

S

S

KD

KD** Preliminary **** Preliminary **

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KSa0(980) is dominantK*(892) is seenSomething else is needed: NR, KSa2(1320), KSa0(1450) , K0(1430), K1(1410) …??

First Observation of First Observation of DD00KKssoo

** Preliminary **** Preliminary **

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First Search for DFirst Search for D0 0

SM Prediction: SM Prediction: 10 10-8-8

Burdman, Golowich, Hewett, Pakvasa Phys. Rev. D66 014009 (2002)

CLEO Results:CLEO Results:

PRL 90, 101801 PRL 90, 101801 (2003)(2003)

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What is CESR-c & CLEO-What is CESR-c & CLEO-c?c?

Run CESR/CLEO at Charm Run CESR/CLEO at Charm ThresholdThreshold– http://www.lns.cornell.edu/CLEO/CLEO-c/

– National Science Board approved in Feb. 2003– CESR-c/CLEO-c has started in June of 2003

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CLEO-c ProgramCLEO-c Program

2004: (3770) ~ 3 fb-1

30 million DD events, 6 million tagged D decays (310 times MARK III)

2005: MeV ~ 3 fb-1

1.5 million DsDs events, 0.3 million tagged Ds decays (480 times MARK III, 130 times BES)

4140~S

2006: (3100), ~1 fb-1 & (3686) ~ 1 Billion J/ decays (170 times MARK III, 20 times BES II)

s L (1032 cm-2 s-1)

3.1 GeV 2.0

3.77 GeV 3.0

4.1 GeV 3.6

Expected Expected machinemachine performance:performance:

CCLLEEOOc

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CLEO-c Future OutlookCLEO-c Future Outlook

Reaction Energy(MeV) L fb-1 PDG CLEO-c

f Ds Ds+ 4140 3 17% 1.7%

f Ds Ds+ 4140 3 33% 1.6%

f D+ D+ 3770 3 UL 2.3%

Decay s L Double PDG CLEOc

fb-1 tags (B/B %) (B/B %)D0 K-+ 3770 3 53,000 2.4 0.6D+ K- ++ 3770 3 60,000 7.2 0.7Ds 4140 3 6,000 25 1.9

Search for Glueballs and HybridsSearch for Glueballs and Hybrids

CLEO-c will take data in Oct of CLEO-c will take data in Oct of 20032003New collaborators are WELCOME!New collaborators are WELCOME!