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Recent Results From CLEO-c. Les Rencontres de Physique de la Vallee D’Aoste February 27 – March 5, 2005. Alex Smith University of Minnesota. Motivation Leptonic D decays Semileptonic D decays Exclusive Inclusive D hadronic BR, s (DD) Conclusions. - PowerPoint PPT Presentation
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Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 1
Recent Results From CLEO-cRecent Results From CLEO-c
Les Rencontres de Physique de la Vallee D’AosteFebruary 27 – March 5, 2005
Alex SmithUniversity of Minnesota
Motivation Leptonic D decays Semileptonic D decays
Exclusive Inclusive
D hadronic BR, (DD) Conclusions
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 2
CLEO-c Detector/CESR-c Accelerator 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)
’
• Addition of superconducting wigglers to CESR required for low energy running– Additional damping to
compensate for lower synchrotron radiation
• Simple conversion of detector from (4S) to (3770) running
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 3
Running at the Running at the (3770)(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
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 4
Impact of CLEO-c MeasurementsImpact of CLEO-c Measurements
• Calibration and validation of Lattice QCD• Test theoretical form factor calculations 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
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 5
CLEO-c + Lattice QCD +B factories + ppbar
CLEO-c + Lattice QCD +B factories
CLEO-c
The Future of Precision Flavor PhysicsThe Future of Precision Flavor Physics
Vub/Vub 15%lB
l
D
Vcd/Vcd 7%lD
Vcs/Vcs =16%l
B D
Vcb/Vcb 5%
Bd Bd
Vtd/Vtd =36%
Bs Bs
Vts/Vts 39% Vtb/Vtb 29%
Vus/Vus =1%
l Vud/Vud 0.1%
e
pn
t
b
W
The Goal: Measure all CKM matrix elements and associated phases in order to over-constrain the unitary triangles
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 6
DD Leptonic Decays: Leptonic Decays: DD++++
• Many large BR tag modes– ~25% Efficiency for
reconstructing a tag• Signal is very pure after
tagging– 28651 +/-207 tag cand.
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:
• Additional charged track presumed to be +
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 7
DD Leptonic Decays: Leptonic Decays: DD++++
MeV 1741202
106.04.15.3 4
Df
DB
Published in PRDPhys. Rev. D, 70, 112004 (2004)
Will also measure Ds++ in run above DsDs threshold
Monte Carlo (1 fb-1)Data (60 pb-1)
First Observation!
0LK
8 candidate events
1 background event in signal region
4X statistics by end of April
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 8
Exclusive Semileptonic D Meson DecaysExclusive 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:
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 9
Exclusive Semileptonic DExclusive Semileptonic D00 Meson Decays Meson Decays
U = Emiss– Pmiss(GeV)
U = Emiss– Pmiss(GeV)
U = Emiss– Pmiss(GeV)
U = Emiss– Pmiss(GeV)
Events
/ (
10
MeV
)Events
/ (
10
MeV
)
Events
/ (
10
MeV
)Events
/ (
10
MeV
) eD0
eD0
eKD0
0*
*0
KK
eKD
(~110 events)
(~30 events)
(~1400 events)
(~90 events)
Cabibbo suppressed modes Cabibbo favored modes
First Observation!
Preliminary
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 10
Exclusive Semileptonic DExclusive Semileptonic D++ Meson Decays Meson Decays
Preliminary
U = Emiss– Pmiss(GeV)
U = Emiss– Pmiss(GeV)
U = Emiss– Pmiss(GeV)
U = Emiss– Pmiss(GeV)
Events
/ (
10
MeV
)Events
/ (
10
MeV
)
Events
/ (
10
MeV
)Events
/ (
10
MeV
) eD 0
eD 0
eKD 0
KK
eKD*0
*0 ,
(~60 events)
(~30 events)
(~500 events)
(~400 events)
Cabibbo suppressed modes: Cabibbo favored modes:
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 11
Exclusive Semileptonic DExclusive Semileptonic D++ Meson Decays Meson Decays
Preliminary
U = Emiss– Pmiss(GeV)
Events
/ (
10
MeV
)
eD
(8 events)
First Observation!
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 12
Exclusive Semileptonic DExclusive Semileptonic D00 Decays Decays
Preliminary
eD
eKD
eKD
eD
eD
eKD
eKD
eD
eD
eKD
eKD
s
s
s
:11
:10
:9
:8
:7
:6
:5
:4
:3
:2
:1
0*
0
0
0
*0
0
0
0
*0
0
Now (60 pb-1):
CLEO-c goal:
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 13
Extracting Decay Constants, FF, |Extracting Decay Constants, FF, |VVcscs| and || and |VVcdcd||
c
du or
e+
W+
ds or
du or
|Vcs| or |Vcd|Use ratio of semileptonic to leptonic branching ratios to eliminate CKM element and isolate hadronic terms:
2
22
31
22
0
02
22
13
DKm
m
D
edqd
f
qfpmm
D
eKD
D
Theory is calibrated/tested with this data
Assuming a precision of ~3% for the SL form factors and ~1% for the decay constants is achieved by the theory:
•Error on |Vcd| of ~1.4% (presently 7%) from D++ and De•Error on |Vcs| of ~1.1% (presently 16%) from Ds
++, Ds
++ and DKl
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 14
Inclusive Semileptonic D Meson DecaysInclusive Semileptonic D Meson Decays
• Tag opposite side D meson
• Identify electron– Select correct e charge
using opposite side D meson:
• Charge of K for D0
• D meson charge for D+/-
• Correct for electron efficiency and backgrounds– Efficiency from reweighted
radiative Bhabhas– Fake rates
Technique:
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 15
Inclusive Semileptonic D Meson DecaysInclusive Semileptonic D Meson Decays
Preliminary
CLEO-c (in D rest frame)
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 16
Inclusive Semileptonic D Meson DecaysInclusive Semileptonic D Meson Decays
%3.0~sysstat:PDG
%2.0~stat:c-CLEO : 0
BR
BRXeD
%9.1~sysstat:PDG
%3.0~stat:c-CLEO :
BR
BRXeD
tag m
ode
tag m
ode
Combiningtag modes:
PreliminaryResults---No BR yet
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 17
DD Hadronic BR’s and Production Cross Sections Hadronic BR’s and Production Cross Sections
e+ e-
DX
ijjiDDij BBNN iiDDi BNN
Single tagged Double tagged
e+ e-
DXj
DXi DXi
ij
j
j
iji
ji
ij
ij
jiDD
N
NB
N
NNN
Independent ofintegrated luminosity!
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 18
DD Hadronic BR’s and Production Cross Sections Hadronic BR’s and Production Cross Sections
Fitting technique• A simultaneous fit for all BR and cross sections is
performed– Charged and neutral modes fit simultaneously
– All correlations taken into account• These systematic errors are included in the fit
• Efficiencies– Denominator of efficiency may be determined using
missing mass in data and MC (all particles measured)• Uncertainty on charged track efficiencies will go down by
factor of four• Improvements to uncertainties on 0 and KS
0 efficiencies nearing completion
0
00
,
, ,
SKKD
KKKD
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 19
DD Hadronic BR’s and Production Cross Sections Hadronic BR’s and Production Cross Sections
22PPEM Kbeambc
beamK EEEE
Key Variables for extracting yields:
Preliminary
Double Tag Yields
~2500 Double Tagged D0
~500 Double Tagged D+
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 20
DD Hadronic BR’s and Production Cross Sections Hadronic BR’s and Production Cross Sections
KD0
Single Tag Yields00 KD KD0
KD 0SKDPreliminar
y
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 21
DD Hadronic BR’s and Production Cross Sections Hadronic BR’s and Production Cross Sections
Preliminary
NDD (1.98 ± 0.04 ± 0.03) x 105
K+ 0.0392 ± 0.0008 ± 0.0023
K+ 0.143 ± 0.003 ± 0.010
K++ 0.081 ± 0.002 ± 0.009
ND+D- (1.48 ± 0.06 ± 0.04) x 105
K++ 0.098 ± 0.004 ± 0.008
KS+ 0.0161 ± 0.0008 ± 0.0015
(e+e DD) 3.47 ± 0.07 ± 0.15 nb
(e+e D+D) 2.59 ± 0.11 ± 0.11 nb
(e+e DD) 6.06 ± 0.13 ± 0.22 nb
ND+D- / NDD 0.75 ± 0.04 ± 0.02
Cross sections:
Neutral Modes:
Charged Modes:
Stat. Errors ~ 2.0%
Stat. Errors ~ 4.5%
%4.91C.L.
160.9
:ResultsFit Global dof
2
N
K+0/ K+ 3.64 ± 0.05 ± 0.17
K+ + -/ K+ 2.05 ± 0.03 ± 0.14
KS+ / K+ + 0.164 ± 0.004 ± 0.006
Ratios:
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 22
DD Hadronic BR’s and Production Cross Sections Hadronic BR’s and Production Cross Sections
• PDG global fit includes ratios to D0K-+ and D+K- ++ – Charged and neutral modes are correlated in that fit
• Our results higher than PDG– Final state radiation (FSR) included in our results and not in PDG results
• 1-2% increase depending on mode
Results shown normalized to PDG valuesPreliminary
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 23
DD Hadronic BR’s and Production Cross Sections Hadronic BR’s and Production Cross SectionsB(D0 K-+)
B(D+ K- ++)
• Branching fractions and cross sections are competitive with world averages with only ~60 pb-1
• Results are presently systematics limited but improving– Dominant per track
systematic error recently improved by factor of 4!
– Most systematic errors will improve with luminosity, however
• Four more D+ modes being added (3X DT statistics)
• These measurements will impact the determination of |Vcb| (from BD*l)
(Bands are PDG average, NOT global fit)
Preliminary
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 24
CLEO-c Impact on the Unitarity TriangleCLEO-c Impact on the Unitarity Triangle
Now: Theory uncertainties dominate
With few % theory errors
made possible by CLEO-c and 500
fb-1 each from the B factories:
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 25
Other CLEO-c Physics Not Covered in This TalkOther CLEO-c Physics Not Covered in This Talk
• (3770)– Data still coming in, luminosity improving
• ’ – Large sample collected... lots of results
– Observation of hc
• Ecm ~ 4140 MeV (just above Ds pair threshold)
– fDs from Ds++
– Ds semileptonic decays
• J/ – Sample of 109 J/’s anticipated– Radiative J/ decays– Glueball candidates, hybrids, ...
Recent CLEO-c Results Alex Smith – University of Minnesota La Thuile ’05 26
SummarySummary
• CLEO-c is producing results that will have a broad impact on the field– These measurements are essential for other
measurements at the B Factories and Tevatron to realize their full potential
• With only 60 pb-1 of (3770) data analyzed many measurements are already the best
• Exciting results on the horizon– More data on (3770)
– Data at Ecm above 2MDs threshold
– J/ radiative decays