1
Recent Results from CLEO-c & CESR-c: A New Frontier in Weak and
Strong Interactions David Asner, University of Pittsburgh
15 June 2005, KAON05 at NWU
CLEO-c Collaboration: ~140 Scientists, 20 Institutions
Carleton, Chicago, Carnegie Mellon, Cornell, Florida, George Mason, Illinois, Kansas, Luther, Northwestern, Minnesota, Pittsburgh, Puerto Rico, Purdue, Rochester, RPI, SMU, Syracuse, Vanderbilt, Wayne State
15 June 2005, KAON05David Asner 2
CLEO-c The Context
Flavor physics is in the “sin 2 era’ akin to precision Z. Over constrain CKM matrix with precision measurements. Discovery potential is limited by systematic errors from non-pert. QCD.LHC may uncover strongly coupled sectors in the physics beyond the Standard Model. The LC will study them. Strongly coupled field theories an outstanding challenge to theory. Critical need: reliable theoretical techniques & detailed data to calibrate them.
Complete definition of pert. and non-pert. QCD Goal: Calculate B, D, , to 5% in a few years, and a few % longer term.
Charm at threshold can provide the data to test & calibrate non-pert. QCD techniques CLEO-c
This Decade
The Future
The Lattice
15 June 2005, KAON05David Asner 3
2005
The discovery potential of B physics is limited by systematic errors from QCD:
Form factors in semileptonic (B) decay ,ub cbV V
Decay constants in B mixing ,td tsV V
D system- CKM matrix elements are tightly constrained to <1% by unitarityMeasurements of absolute rates for leptonic and semileptonic D decays
yielding decay constants and form factors to test QCD techniques.thatcan then be applied to the B system. + determinations of Vcs Vcd
Precision Quark Flavor Physics: Role of Charm
Bd Bd
In addition as Br(B D)~100% absolute D branching ratios normalize B physics.
|f(q2)|2
|VCKM|2
CLEO-c program
Probe of new physics: Dmixing, DCPV, D rare (& strong phases for CKM angle γ)
J/ probe of glueballs and exotics test of QCD Not covered today
15 June 2005, KAON05David Asner 4
Lattice predicts fB/fD with a small errorIf a precision measurement of fD existed (it does not)Precision Lattice estimate of fB precision determination of Vtd
Similarly fD/fDs checks fB/fBs precise once Bs mixing seen
Importance of measuring absolute charm leptonic branching ratios: fD & fDsVtd & Vts
2 2 2( .) Bd td tbV Vra n fte co st
1.0%
(expt)
Winter 2005
td tbV V
if was known to 3%
would be known to ~5%Bdf
tdV1
ubV
~15% (LQCD)hep-lat/0409040
Bd Bd
22( ) / ( .)D cdD
B D const f V
|fD|2
|VCKM|2
s inaccessible
accessibleBd B
D Ds
f f
f f
td tsV / V
known from unitarity to 1%cdV
~ 16%
D
fD+/fD+~100%
PDG’04
15 June 2005, KAON05David Asner 5
|f(q2)|2
|VCKM|2
HQS
1) Measure D form factor in Dl. Tests LQCD D form factor calculation2) BaBar/Belle can extract Vub using tested LQCD calc. of B form factor3) Needs precise absolute Br(Dl) & high quality d(Dl)/dE neither exist
2 D 2 2cd2
|V | |f (q )|q
d
d
b u l B
c dl D
Importance of Absolute Charm Semileptonic Decay Rates
When Vub is determined from
exclusive semileptonic (B) decay
(5.1% 6.0% 12.6%)| |
ub
ub
V
V
Stat sys form factorUnquenched LQCD or sum rulesExpt. Error
2 B 2 2ub2
|V | |f (q )|q
d
d
~ 45%
PDG04
B
B
Charm semileptonic decaystest form factor predictions
2 2
&
16 representative
error budget for new
analysis
Belle BABAR B l
q GeV
BABAR
unitary constrains |Vcd| to 1%
15 June 2005, KAON05David Asner 6
3exp(41.4 1.0 1.8 ) 10cb theoV
Importance of precision absolute charm hadronic branching ratios
As B Factory data sets grow, & calculation of F improve
dB(DK)/dB(DK) dVcb/Vcb=1.2%
Vcb zero recoil in B D*l+ & B Dl+
2* 2 22
( ) ( ) cb
dB D F q V
dq
2 2max( ) 0.91 0.04F q q
Lattice & sum rule
ALEPH, DELPHI,L3,OPAL.BABAR/BELLE,ARGUS/CLEO/CDF
Test models of B decay ex: HQET & factorization:
Understanding charm content of B decay (nc)
Precision Z bb and Z cc (Rb & Rc)
At LHC/LC Hbb Hcc
(World Average Summer 2004)
Now: several key charm branchingratios have errors between 7-26%
need B(DK)
becomessignificant
15 June 2005, KAON05David Asner 7
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
15 June 2005, KAON05David Asner 8
CLEO-c Run Plan & Status
2002: Prologue: Upsilons ~4 fb-1 at (1S),(2S),(3S) (combined) 10-20 times the existing world’s data (Nov 2001-Nov 2002)
Nominal CLEO-c Run Plan: 1 year at each of1: (3770) 2: above Ds threshold 3: J/
CLEOc
A 3 yearprogram
2003: Installed 1 prototype wiggler spring ‘03 Took ~5 pb-1 at (3770), 3 pb-1 (2S) Installed ½ production wigglers summer’03Pilot Run I: (3770), (2S), continuum
55.8 pb-1 3 pb-1 20.5 pb-1
Installed ½ production wigglers spring’04Pilot Run II+III: only (3770) 225.3 pb-1
MACHINECONVERSION
Scan of Ds threshold region later this summer
PAC to advise on priorities of run plan: Nov ‘05
15 June 2005, KAON05David Asner 9
CLEO-c & D Tagging
Dtag
Dsig
K
Tag one D meson in a selected tag mode.Dictates whether final state is D+D- or D0D0
Study decays of other D, (signal D)
2 2
| |
bc beam D
beam D
miss miss
M E p
E E E
U E P
ED Ebeam improves mass resolution by ~10X
e+
e+e- (3770)DD
e-
Pure DD final state, no additional particles (ED = Ebeam). Low particle multiplicity ~ 5-6 charged particles/event Good coverage to reconstruct in semileptonic decays Pure JPC = 1- - initial state
Leptonic Decays: Dtag + (Dsig ) Semileptonic Decays: Dtag + (Dsig Xee), reconstruct e using Pmiss
Hadronic Decays: double-tag yields & single-tag yields determine BR
Analysis Preview
15 June 2005, KAON05David Asner 10
Summary of CLEO-c Impact
Leptonic Charm Decays – D++, Ds+ +,+ Measure decay constants fD, fDs ~few% Improved fB possible from CLEO-c fD measurement + LQCD
Semileptonic Charm Decays – D0,D+K(*)l, (l - Ds+ K(*)l, ()l
Measurements of |Vcs| and |Vcd| Test theoretical form factor models Impacts prediction of form factors for B meson decays Important for |Vub| and |Vcb|
Hadronic Charm Decays – D0K, D+K, Ds+ Important for |Vcb|
General Themes: Charm measurements interesting in their own right Calibration and validation of Lattice QCD Improved measurement of many normalization modes for B
physics
15 June 2005, KAON05David Asner 11
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
15 June 2005, KAON05David Asner 12
Selected CLEO-c Publications Measuring B(D+ MU+ NU) and the Pseudoscalar Decay Constant f(D+).
Phys.Rev.D70:112004,2004 (Paper on 55.8 pb-1, update with 281.1 pb-1 at LeptonPhoton2005)
Absolute Branching Fraction Measurements of Exclusive Charged D Semileptonic Decays - to be submitted to PRL, CLNS 05-1906 (Paper on 55.8 pb-1)
Absolute Branching Fraction Measurements of Exclusive Neutral D Semileptonic Decays - to be submitted to PRL, CLNS 05-1915 (Paper on 55.8 pb-1)
Inclusive D0/D+ Absolute Branching Fraction Measurements (results with 281.1 pb-1 at LeptonPhoton2005)
Measurement of Absolute Hadronic Branching Fractions of D Mesons and e+e- DD Cross Sections at Ecm=3773 MeV submitted to PRL – hep-ex/0504003 (Paper on 55.8 pb-1)
15 June 2005, KAON05David Asner 13
Leptonic Decays: D+→μ+ν
2
2222 2
218
lFl cdD D
D
mGD l f m M V
M
15 June 2005, KAON05David Asner 14
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
S=3 B=0.33
BESII Phys.Lett.B610:183-191, (2005)
p
MKIII
BESII
15 June 2005, KAON05David Asner 15
D Leptonic Decays: D++
Many large BR tag modes ~25% efficiency for
reconstructing a tag Signal is very pure after
tagging 28651 +/-207 tag candidate
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 +
15 June 2005, KAON05David Asner 16
D Leptonic Decays: D++
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
Data (~60 pb-1)
First Observation!
0LK
8 candidate events1 background event in signal region
MC (~1.7 fb-1)
15 June 2005, KAON05David Asner 17
Comparison with LQCD + Models
150 180 210 240 270 300 330 360 390 420 450 480 510
Charged D Decay Constant (MeV)
• BES• Lattice 2004• CLEO-c• Isospin Mass Splittings• Potential Model• Rel. Quark Model• QCD Sum Rules• QCD Spectral Sum Rules• MILC• UKQCD
Now: LQCD error ~10%
CLEO-c error ~60 pb-1 22%
~280 pb-1 <10% error
Eventually expect few % precision on fD+ & fDs
15 June 2005, KAON05David Asner 18
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 DVln, except 3 FF’s enter
Can also form ratios, where theory should be more precise
223
322
24qf
pVGPlD
cqF
15 June 2005, KAON05David Asner 19
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:
15 June 2005, KAON05David Asner 20
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)
CLNS 05-1906 and CLNS 05-1915 to besubmitted to PRL
15 June 2005, KAON05David Asner 21
More Cabibbo allowed modes
U = Emiss– |Pmiss| (GeV)
Events
/ (
10
MeV
)
Events
/ (
10
MeV
)
Events
/ (
10
MeV
)
(~550 events)
U = Emiss– |Pmiss| (GeV)
U = Emiss– |Pmiss| (GeV)
cs Cabibbo Favored 55.8 pb-1 Data
(~90 events)
(~420 events)
Historically Cabibbo allowed modes: provide a significantbackground to Cabibbosuppressed modes, makingthe latter particularlychallenging…..
D+K0e+D+K*0e+K*0K-+
D0 K*-e+K*-K-0
15 June 2005, KAON05David Asner 22
Cabibbo suppressed modes0D e
0D e
U = Emiss– |Pmiss| (GeV)
Events
/ (
10
MeV
)
(~110 events)
Events
/ (
10
MeV
)
eD 0
(~65 events)
U = Emiss– |Pmiss| (GeV)
55.8 pb-1 Data
Compare to:state of the art measurementat 10 GeV (CLEO III)PRL 94, 11802
Note:kinematicseparation.
Tag with D*DpObservable: m=mD*-mD.
m
15 June 2005, KAON05David Asner 23
*0D K e n+ +®
2(GeV/c )mpp
U = Emiss– |Pmiss| (GeV)
(~30 events)
U = Emiss– |Pmiss| (GeV)
(~30 events)
(8 events) (5)
1st Observation1st Observation
E791 Phys.Lett.B397:325-332,(1997)Relative rate:
S/N ~1/2S/N ~15/1
More Cabibbo supressed modes - 55.8 pb-1
Only measurementuntil now
D+e+
D+e+
D0e+
D0 K*-e+K*-K-0
eKD
eD0*
0
U = Emiss– |Pmiss| (GeV)
15 June 2005, KAON05David Asner 24
Exclusive Semileptonic D Decays
Preliminary
Now (55.8 pb-1):
Will also measure D+sK0e+,K*0e+,e+
in run above DsDs threshold
CLEO-c already all modes more precise than PDG.
to be submitted to PRL
15 June 2005, KAON05David Asner 25
Decay Constants, FF, |Vcs| and |Vcd|
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 ~few% (presently 7%) from D++ and De•Error on |Vcs| of ~few% (presently 16%) from Ds
++, Ds
++ and DKl
15 June 2005, KAON05David Asner 26
Differential Semileptonic Rates PPe
D0→K-e+ν D0→π-e+ν
2 2 2cs,d2
|V | |f (q )|q
d
d
Raw q2 No efficiency correction
2q
d
d
2q
CLEO PRL 94/, 11802
(PRL 94, 011601 (2005)
STATUS2005 (CLEO IIIFOCUS BES II)
LQCD : shape & rate correct: precision~10%
22
2
2
~ 0.4GeV CLEO q
~ 0.025 GeV CLEO-c
q
(1) No kinematic ambiguity (2) rest frame of D q2 resolution x 16 better
e
Ke
CLEO-c
2
d
dq
shape
rate
First unquenched LQCD for D/K e
15 June 2005, KAON05David Asner 27
U = Emiss - Pmiss
CLEO-c: PS PS & PS V absolute form factor magnitudes & slopes to a few%. Stringent test of theory! (Unique)
D0 l
D0 Kldp
d
(GeV/c)p
CLEO-c MC
Lattice QCD
dp
dD0 l
D0 l
CLEO-c MC
(GeV/c)p
1fb-1
(D+ l(D+ lindependent of Vcd tests amplitudes ~few%
(DsKln) / (Dsl) independent of Vcs tests amplitudes ~ few%
Vcs/Vcs=few%(now~11%) Vcd/Vcd=few%(now: 5.4%)D Ke
Testing the Lattice with (semi)leptonic Charm Decays
D e
Then Tested lattice to calc. Bl is available for precise exclusive Vub
1fb-1
15 June 2005, KAON05David Asner 28
Inclusive Semileptonic D Decays
Preliminary
CLEO-c (in D rest frame)
15 June 2005, KAON05David Asner 29
Inclusive Semileptonic D 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 re-
weighted radiative Bhabhas
Fake rates
Technique:
CLEO-c(stat.)<0.2%<0.2%
15 June 2005, KAON05David Asner 30
Hadronic D Decays
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!
K
K
Submitted to PRLhep-ex/0504003
15 June 2005, KAON05David Asner 31
D Hadronic BR’s & 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 Efficiencies
Denominator of efficiency may be determined using missing mass in data and MC Data-MC agreement on the order of <0.2% for charged tracks MC-data agreement for p0 and K0
s efficiencies still undergoing refinements
Include effects of final state radiation (FSR)
KKKK
KKKD
KKKD
SS
S
, ,
, , ,
, ,
000
00
00
15 June 2005, KAON05David Asner 32
Absolute Charm Branching Ratios at Threshold
# ( )Observed in tagged events( )
detection efficiency for ( ) #D tags
KB D K
K
Independent ofIndependent ofL and cross L and cross sectionsection
Single tags
D candidate mass (GeV)
Double tags
D K
,
D
D K
K
2 2| |BC beam DM E p
D candidate mass (GeV)
Dbeam EEE Kinematics analogous to (4S)BB: identify D with
(MBC) ~ 1.3 MeV, x2 with 0
(E) ~ 7—10 MeV, x2 with 0
:D beamE E
15120±180 377±20
: 10 /D beam bc bcE E M M
15 June 2005, KAON05David Asner 33
(log scale)!
2484±51(combine
d)
1650±42(combined)
6 D+ Modes6 D+ Modes3 D0 Modes3 D0 Modes
Single tags Double tags
Signal shape: (3770) line shape, ISR, beam energy spread & momentum resolution, Bgkd: ARGUS
Global fit pioneered by Mark IIINDD & Bi’s extracted from single and double tag yields with 2 minimization technique.
D0 D0
D+ D+
i i iDDN N B ijjiDDij BBNN
ij ji
j ij
i j ij
DDij i j
NB
N
N NN
N
15 June 2005, KAON05David Asner 34
submitted to PRL
Stat. errors: ~2.0% neutral, ~2.5% charged(systematic) ~ (statistical).
syst. dominatesMany systematics evaluated using data so will shrink as L
D0 ModesD+ Modes
Normalized to PDG
six modes more precise than PDG.
(DD)=6.390.10+0.17 –0.08 nb 01.002.078.0
00
DDee
DDee
15 June 2005, KAON05David Asner 35
Comparison with PDG 2004
B (%) Error(%) Source
3.820.070.1 3.6 CLEO
3.820.090.1 3.8 ALEPH
3.80 0.09 2.4 PDG
3.910.08 0.09 3.1 CLEO-c
CLEO & ALEPHD*++Do, Do K-+ compare to:D*++Do, Do unobserved(Q~6MeV)
THEN:
NOW:
Do K-+
CLEO-c as precise as anyprevious measurement
+
thrust
CLEO-c
15 June 2005, KAON05David Asner 36
1
0
Decay / (%)
2004 1
2.4 3.1 0.5( )(1.3)
7.7 3.9 0.6( )(1.5)
12.5% ( ) 3.2S
B B
PDG CLEO fb
D K stat sys
D K stat sys
D BABAR
CLEO-c will set absolute scale for all heavy quark measurements
B (%) Error(%) Source
9.30.60.8 10.8 CLEO
9.11.30.4 14.9 MKIII
9.10.7 7.7 PDG
9.52 0.250.27 3.9 CLEO-c
0 0*
* 0
( )
( ( ))
( )B D BD
B D D
D
D K
K
B
Method (CLEO) Bootstrap:Measure:
THEN:
Assume isospin
NOW:
B(D+K-
Conclusion: the charm hadronic scale we have been using for last 10 years is approximately correct
Mostprecise
15 June 2005, KAON05David Asner 37
Impact of CLEO-c Measurements
Results from ~55.8 pb-1: Accumulated ~281 pb-1
Leptonic Charm Decays – D++, Ds+ +,+ Measure decay constants fD, fDs ~few% Improved fB possible from CLEO-c fD measurement + LQCD
Semileptonic Charm Decays – D0,D+K(*)l, (l - Ds+ K(*)l, ()l
Measurements of |Vcs| and |Vcd| Test theoretical form factor models Impacts prediction of form factors for B meson decays Important for |Vub| and |Vcb|
Hadronic Charm Decays – D0K, D+K, Ds+ Important for |Vcb|
Vcd Vcs Vcb Vub Vtd Vts
7% 16% 5% 15% 36% 39%
few% few% few%
few%
few%
few%
PDG
B-Factory/Tevatron Data & CLEO-c Lattice Validation
PDG
CLEO-c data and LQCD
15 June 2005, KAON05David Asner 38
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:
15 June 2005, KAON05David Asner 39
Summary
CLEO-c 1st data (6 wigglers) summer presented in summer 2004.Detector performing well, data is excellent quality & is well understood.fD+ is now known to 22% (was 100% in PDG’04, <10% at LP2005) D0-e+ now 14% (was 45%), 1st observations: D0 e+, D+ e+
Most precise measurements of D+ K-+ +
Several % precision in all key charm quantities, + probe for new physics & glueballs
Lattice goal: Calculate in D,B,, to 5% in few years & few% longer term CLEO-c about to provide few % tests of lattice calculations (& other QCD techniques) in D system & in onia, quantifying the accuracy for application of LQCD to the B systemBABAR/Belle/CDF/D0 (later LHC-b/ATLAS/CMS SuperKEKb) + theory can reach few % precision for Vtd, Vts, γ and exclusive Vub,Vcb.CLEO-c maximizes the sensitivity of the worldwide heavy quark flavor physics program to new physics this decade and paves the way for understanding beyond the Standard Model physics at the LHC/LC.
15 June 2005, KAON05David Asner 40
Other CLEO Physics Not Covered
(3770) Search for CPV, rare decays DKee, mixing Rich program of Dalitz plot analyses important for CKM angle
Measurement of D0/D0 relative strong phase Separate measurements of B(D->K S,L)
Search for nonDD final states
’ + other charmonia... lots of results Observation of hc, photon transitions, 2-photon width c2
’XJ/, VP, multibody, baryon-anti-baryon J/ di-leptons
Bottomonia from 2002 run (1-3S)gg, LFV, (1S) h+h-,00,,’ , ee
’b->b transitions
hidden beauty to open charm
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