Semileptonic D Decays Semileptonic D Decays from CLEO and BELLEfrom CLEO and BELLE

Yongsheng GaoSouthern Methodist University

(CLEO Collaboration)

ICHEP04, Beijing, Aug. 16 ─ 23, 2004ICHEP04, Beijing, Aug. 16 ─ 23, 2004

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ICHEP Abstract/Paper

First CLEO-c Inclusive DFirst CLEO-c Inclusive D00,D,D++ semileptonic Decays semileptonic Decays (ICHEP ABS11-0777, CLEO CONF 04-12)(ICHEP ABS11-0777, CLEO CONF 04-12)

First CLEO-c Exclusive DFirst CLEO-c Exclusive D00 semileptonic Decays semileptonic Decays

(ICHEP ABS8-0781, CLEO CONF 04-3)(ICHEP ABS8-0781, CLEO CONF 04-3)

CLEO-III Exclusive DCLEO-III Exclusive D00 semileptonic Decays semileptonic Decays (ICHEP ABS11-0780, CLEO CONF 04-14)(ICHEP ABS11-0780, CLEO CONF 04-14)

BELLE Exclusive DBELLE Exclusive D00 semileptonic Decays semileptonic Decays (ICHEP ABS11-0706, BELLE CONF 0457)(ICHEP ABS11-0706, BELLE CONF 0457)

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IntroductionIntroduction

Outline

First CLEO-c Semileptonic D Decay ResultsFirst CLEO-c Semileptonic D Decay Results

– Inclusive D0 Xe+ D+ Xe+

(ICHEP ABS11-0777)(ICHEP ABS11-0777)

– Exclusive D0 K-e+-e+-e+, ρ-e+ (ICHEP ABS8-0781, CLEO CONF 04-3)(ICHEP ABS8-0781, CLEO CONF 04-3)

Future OutlookFuture Outlook

CLEO-III Semileptonic D Decay ResultsCLEO-III Semileptonic D Decay Results

– Exclusive D0 K-l+-l+ (ICHEP ABS11-0780, CLEO CONF 04-14, Submitted to (ICHEP ABS11-0780, CLEO CONF 04-14, Submitted to

PRL)PRL)

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ud us ub

CKM cd cs cb

td ts tb

V V V

V V V

V V V

V

Why Semileptonic D Decay?

D0 Xe+ and D+ Xe+

– Inclusive semileptonic BR and spectrum

D0 K-e+, -e+etc:

– Form Factors, Vcd , Vcs and Vub

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CESR and CLEO

Tracking: Drift ChambersElectron ID: CsI Cal.

Hadron ID: RICH

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CLEO Data Samples

Resonance Integrated Luminosity

CLEO III ~ (4S) 9.2 fb-1

CLEO-c (3770) 60 pb-1

Mass (GeV/c2)

(3770)

(2S)

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Event Reconstruction: D*++slowD0

(K) l Observable: M = MD* - MD0

CLEO III D0 K- l+/- l+

~7 fb-1 of CLEO-III data near (4S)

D0Kl

D0 l

D0Kl 2% K-faking-, 87% efficiency

D0 l

K/ Separation Capability Essential!

M (GeV)

No PID

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CLEO III D0 K- l+/- l+

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0.05 0.1 0.15 0.2

Ratio of Branching Fractions

E687 1996

CLEO II 1995

Mark III 1988

CLEO III

Existing Measurements:

~7 fb-1 CLEO III data near (4S) Kl l

=0.0820.006(stat)0.005(sys)

Submitted to PRL

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eKe

CLEO III D0 K- l+/- l+

Submitted to PRL

First Measurement

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(3770) ~(4S)

Charm at (3770) vs ~(4S)

– Large Cross-Section

– Low Multiplicity– NO Fragmentation– Kinematics Variables:– “Background Free”

∆∆E =E = E Ebb - E - EDD U =U = E Emissmiss - P - Pmissmiss

K-

e+

K+

-

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K+

-

ee+

D0

K-,-,K*-,ρ- or X

D0

e+

Unique Kinematics at (3770)

Tag

No PID

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Fully Reconstructed D0 (Tag) 6

0K

fully

recon

stru

cte

d D

0

Fro

m 6

0 p

b-1

at

(3770)

Preliminary

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Electron Identification

Radiative BhabhaE/p, dE/dx, RICH

Preliminary

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Stat. Uncertainty ~0.5%PDG: BR = (6.750.29)%

Stat. Uncertainty ~ 0.6%PDG: BR = (17.21.9)%

CLEO-c DATA

Electron Momentum (GeV/c) Electron Momentum (GeV/c)

Nu

mb

er O

f ev

ent

/(50

MeV

/c)

Nu

mb

er O

f ev

ent

/(50

MeV

/c)

CLEO-c DATA

Corrected Electron Spectra

D0 Xe+D+ Xe+

From 60 pb-1 of first CLEO-c data: Preliminary

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Crossfeed bw D0 K-e+-

e+

M (GeV)0.12 0.22

D0 l

D0Kl

~(4S)

D0K-e+

D0-e+(3770)

~(4S): NONO separation in ∆M separation in ∆M

(3770): WELLWELL separated in U separated in U

No PID No PID

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CLEO-c: D0 K-e+ Results

From 60 pb-1 CLEO-c data: Preliminary

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CLEO-c Exclusive D0 Semileptonic

D0K-e+

D0K*-e+

D0-e+

D0ρ-e+

Pre

limin

ary

First Observation

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First CLEO-c Results

Improved measurements of absolute Branching Fractions

First Observation of D0 ρ-e+Both Statistic/Systematic errors limited by the 60 pb-1 data!

Expect ~3 fb-1 of CLEO-c data in one year!

Pre

limin

ary

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Summary

Many very precision charm results: Many very precision charm results:

Form factors, Absolute BR, CKM elements … Form factors, Absolute BR, CKM elements …

“Background Free” at (3770)

Limiting Factor: 60 pb-1 of data sample!

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CLEO-c Outlook

2006: MeV ~ 3 fb-1

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

4140~S

2005: (3770) ~ 3 fb-1

18 million DD evts, 3,6 million tagged D decays (150 times MARK III)

2007: (3100), ~1 fb-1 & (3686) ~ 1 Billion J/ decays (170 times MARK III, 20 times BES II)

CCLLEEOOc

Many very precision charm results: Many very precision charm results:

Form factors, Absolute BR, CKM elements … Form factors, Absolute BR, CKM elements …

CLEO-c Yellow Book, CLNS-01/1742