semileptonic d decays from cleo and belle
DESCRIPTION
Semileptonic D Decays from CLEO and BELLE. Yongsheng Gao Southern Methodist University (CLEO Collaboration) ICHEP04, Beijing, Aug. 16 ─ 23, 2004. CLEO. ICHEP Abstract/Paper. CLEO-III Exclusive D 0 semileptonic Decays (ICHEP ABS11-0780, CLEO CONF 04-14). - PowerPoint PPT PresentationTRANSCRIPT
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
Southern Methodist UniSouthern Methodist Univ.v.
Yongsheng Gao Yongsheng Gao 2
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)
Southern Methodist UniSouthern Methodist Univ.v.
Yongsheng Gao Yongsheng Gao 3
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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Yongsheng Gao Yongsheng Gao 4
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
Southern Methodist UniSouthern Methodist Univ.v.
Yongsheng Gao Yongsheng Gao 8
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
Southern Methodist UniSouthern Methodist Univ.v.
Yongsheng Gao Yongsheng Gao 15
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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Yongsheng Gao Yongsheng Gao 18
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