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Hadronic Charm Decays in CLEO Steven Blusk, Syracuse University (on behalf of the CLEO Collaboration) XXXIII International Conference on High Energy Physics July 26 – August 2, 2006, Moscow, Russia. Introduction D s Scan D 0 , D ± Branching Fractions Cabibbo favored Cabibbo-suppressed - PowerPoint PPT Presentation
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Steven Blusk, Syracuse University 1
Hadronic Charm Decays in CLEO
Steven Blusk, Syracuse University(on behalf of the CLEO Collaboration)
XXXIII International Conference on High Energy Physics
July 26 – August 2, 2006, Moscow, Russia Introduction Ds Scan D0, D± Branching Fractions
Cabibbo favored Cabibbo-suppressed
Ds Branching Fractions Inclusive , and Exclusive CF
Amplitude Analyses D0 ++
D0 K+K-0
Summary
Other CLEO Charm TalksLeptonic Charm decays Sheldon Stone (this session) Semileptonic Charm decays Yongsheng Gao Session 10-3DCSD, DK S. Blusk, Session 8-2Y(4260) at CLEO Ian Shipsey, Session 9-3Charmonium decays at CLEO Tomasz Skwarnicki, Session 9-4
Steven Blusk, Syracuse University 2
The Charm Landscape Near Threshold
DD
S SD D* *D D
*S SD D * *
S SD D
*D D
(3770) (4160)
(3770)DD Pure C=-1 No addn’l particles Low multiplicity Clean recon.
CLEO
Lep & SL decays isolate the strong interaction effectscritical checks on LQCD, modelsHadronic BF’s needed for normalization of B BF’s, strong phases, strong int. effects+…
E>3940 MeV for Ds
production
Ds Scan – next 2 slides
e+ e-DD
(3770)DD
Steven Blusk, Syracuse University 3
No need to reconstruct D*, as Mbc differentiates event types.
For DD and DsDs cut on E and use Mbc to extract yields.
For other event types cut on Mbc and use invariant mass to extract yield.
DD
DsDs*
DD DsDs
DD*
D*D*
E > = 0
Ecm=4160 MeV Simulations
The Ds Scan
12 scan points~60 pb-1 (total)
Scan the region 3970-4260 MeV Optimize Ds physics Study D(s) XS in this region Confirm Y(4260)
Ecm=4160 MeV selected Additional 180 pb-1 collected at 4160 MeV
DD
*
SSD D
S SD D
* *S SD D
*DD * *D D
Steven Blusk, Syracuse University 4
Inclusive DInclusive Hadrons
Exclusive DD
Total Charm & Multibody
D*+
D0
X
e+
e-
D0 Momentum (GeV/c)
DD
*DD
* *D D
D*D
No DD observed (using similar MM
technique)
Three ways to determine hadronic cross-section: Inclusive hadronic event counting Inclusive D meson Exclusive D(*) D(*) final states
Are there multi-body events?Look for D*+Dwith p(D*)<400 MeV (below kinematic limit for D*D* events)
Clear that exclusive final states do not saturate the total charm XS.
Steven Blusk, Syracuse University 5
D Hadronic BF (Cabibbo-Favored)
2i j ij
DDij i j
ij ji
j ij
N NN
N
NB
N
Since ij i j, correlated systematics cancel in NDD
To first order, Bi is independent of tag modes’ efficiencies, ,L.
Use 3 D0 and 6 D+ modes - Count #Single Tags (ST): Ni
obs (9 modes) - Count # Double tags (DT): Nij
obs (45 pairs of modes)
Expected #ST:Expected #DT:
expij i j ijDDN N B B
exp 2i i iDDN N B
Double Tagged, 281 pb-1
Update from 57 pb-1 to 281 pb-1 underway
Some systematics still being studied.
O(1%) stat & syst errors on golden modes in sight…
Preliminary
Steven Blusk, Syracuse University 6
D Hadronic BF (Cabibbo-Suppressed)B (10-3) CLEO-c PDG (10-3)
1.39 ± 0.04 ± 0.03 1.38 ± 0.05
0.79 ± 0.05 ± 0.04 0.84 ± 0.22
13.2 ± 0.2 ± 0.5 11 ± 4
7.3 ± 0.1 ± 0.3 7.3 ± 0.5
9.9 ± 0.6 ± 0.7 ---
4.1 ± 0.5 ± 0.2 ---
1.25 ± 0.06 ± 0.08 1.33 ± 0.22
3.35 ± 0.10 ± 0.20 3.1 ± 0.4
4.8 ± 0.3 ± 0.4 ---
11.6 ± 0.4 ± 0.7 ---
1.60 ± 0.18 ± 0.17 1.82 ± 0.25
+0 ++- +00
++-0 +++-- ++
+- 00
+- +-0+- +-
+-0
+- 00 Isospin Analysisof final stateA(I=2)/A(I=0) = 0.420±0.014 ±0.010Strong phase shift: = (86.4±2.8±3.3)0
Large FSI in D decays..Other first/improved BF’sD00, +-, D++
Steven Blusk, Syracuse University 7
Inclusive D(s) Hadronic Decays Inclusive ss rates expected to be higher for Ds
+ than D0/D+.
Ds(,+X ingredient in one method of measuring Bs fraction in Y(5S) decays.
CLEO-c measurements with 281 pb-1 D0/D+ (3770 MeV) and 71 pb-1 Ds
+ (4170 MeV).
Fully reconstruct one D(s), search for , on other side, subtract sideband.
includes feed-down from ´.
152K tags228K tagsD0 X D+ X Ds
+ X3K tags
B (%) PDG
D0 9.4 ± 0.4 ± 0.6 <13%
D 5.7 ± 0.5 ± 0.5 <13%
Ds 23.7 ± 3.1 ± 1.9 -
B ´ (%) PDG
D0 2.6 ± 0.2 ± 0.2 -
D 1.0 ± 0.2 ± 0.1 -
Ds 8.7 ± 1.9 ± 0.6 -
B (%) PDG
D0 1.0 ± 0.1 ± 0.1 1.7 ± 0.8
D 1.1 ± 0.1 ± 0.2 <1.8
Ds 16.1 ± 1.2 ±0.6 18 +15 -10
Much larger rates for Ds as anticipated.
Steven Blusk, Syracuse University 8
Exclusive Ds Hadronic Decays
Mode DS+ DS-
KsK+ 1055±39 928±37
K+K-+ 4316±89 4350±89
K+K-+ 1160±85 1251±84
+-+ 970±80 947±78
+ 547±50 570±50
+ 362±23 372±24
Double Tag Yields
Ds hadronic BF’s, particular , critical. BF~20% Follows very similar procedure as for (3770)DD
inv vs Mbc driven by DsDs* kinematics.
Look at 6 modes: KsK+, K+K-+, K+K-+, +-+,+,+
Double Tag yieldsdetermined via sidebandsubtraction
Signal region
Sideband regions
Steven Blusk, Syracuse University 9
Ds Hadronic BF’sLikelihood fit used to extract BF’s
Errors already << PDG
Preliminary
Ds+ partial BF:CLEO-c (±10 MeV around ) 1.98±0.12±0.09 (~x2+O(10%)) (Preliminary !!)
DsK+Kyield vsK+K- mass
Ds is a critical measurement, but must be careful Interference & cross-feed with nearby f0(980) is an issue Define a partial BF within some window around the . This is actually what experimentalists need
For reference: Ds+
PDG06: 4.4±0.6BaBar: 4.8±0.5±0.4 (1.008<M(K+K-)<1.035 GeV)
Steven Blusk, Syracuse University 10
D+ +-+ Dalitz Analysis - Motivation
Projections/Fits Isobar Model
σ required, implemented as a BW resonance
FOCUS: K-matrix approach - No need for a , employed a () S-wave to describe data
Although not entirely clear this is correct:“… the K-matix approach employed in Ref [5] does not meet the chiral requirementsof a soft expansion for low energies…” [J. Oller, PRD71 054030]
Can CLEO-c confirm, refute, add more confusion to the saga?
No
With
But BW does not account for phase variation across the Dalitz plot [D. Bugg hep-ph/0510021]
E791
BESII- J/
Described viaa complex pole
Steven Blusk, Syracuse University 11
• L=281 pb-1 @ (3770)• Untagged analysis• Signal box for DP
– |ΔE|<2– |mBC-mD|< 2
• Backgd boxes for DP– |ΔE|<2– 5<|mbc-mD|<9
DP Statistics: N(π−π+π+) ~2600 ev. N(Ksπ+) ~2240 ev. Nback ~ 2150 ev.
D+ +-+ Dalitz Analysis
6991 on DP
Signal~2600
ev.
D+→π−π+π+
D+→K0Sπ+
Steven Blusk, Syracuse University 12
D+ +-+ Dalitz Results (Preliminary)Mode Fit Values
Relative
Amplitude
Phase(degrees)
Fit Fraction (%)
(770)+ 1.0 0 20.0±2.3±0.9
f0(980)+ 1.4±0.2±0.2 12±10±5 4.1±0.9±0.3
f2(1270)+ 2.1±0.2±0.1 237±6±3 18.2±2.6±0.7
f0(1370)+ 1.3±0.4±0.2 -21±15±14 2.6±1.8±0.6
f0(1500)+ 1.1±0.3±0.2 -44±13±16 3.4±1.0±0.8
pole 3.7±0.3±0.2 -3±4±2 41.8±1.4±2.5
Limits on Other Contributing Modes
(1450)+
0.9±0.5 51±22 <2.4
f0(1710)+ 1.0±1.5 -17±90 <3.5
f0(1790)+ 1.0±1.1 23±58 <2.0
Non-resonant
0.17±0.14 -17±90 <3.5
I=2 ++
S-wave0.17±0.14 23±58 <3.7 Consistency with E791
- E791 BW Fit Fraction = (46.3±9.0±2.1)% pole provides a good description of the DP
2 21( ) , where, (0.47 0.22) GeVA
A
Pole s s is s
Likelihood Fit including: Amplitude, phase, spin-dependent PW (ie. BW), angular distribution, Blatt Weiskopf angular momentum penetration factor.
Steven Blusk, Syracuse University 13
D0K+K-0 Dalitz Analysis (1) Motivation:
CKM angle can be measured using interference betweenB+ D0K+ and B+D0K+ and the CC modes. [GLS, PRD 67 071301 (2003)] Two of the key inputs are rD and D, defined through:
rD and D can be independently determined by analyzing the D0K+K-0 DP.
0 *
0 *
( )
( )Di
D
A D K Kr e
A D K K
Uses ~9 fb-1 of data collected on/just below (4S) Reconstruct D*+D0+, D*-D0-
Charge of bachelor tags the D0 flavor at production Signal/sideband regions as shown 735 Signal candidates
Analysis Overview
Steven Blusk, Syracuse University 14
D0K+K-0 Dalitz Analysis (2)Similar fitting technique to D +-+ analysis
Mode Fit Values
Relative
Amplitude
Phase(degrees)
Fit Fraction (%)
1.0 0 46.1±3.1
0.52±0.05±0.04 332±8±11 12.3±2.2
+ 0.64 ±0.04 326±9 14.9±1.6
NR 5.62±0.45 220±5 36.0±3.7
Read off the values from the DP fit
rD= 0.52±0.05±0.04D = (332±8±11)o
First measurement of D. Significant improvement on rD over previous value using K*K BF’s
K*+
K*-
K*+
Steven Blusk, Syracuse University 15
Next-to final remarks
Some more details, recent talks, pubs on these topics Ds Scan:
R. Poling, CHARM2006, “New results of the CLEO-c scan from 3970-4260” S. Blusk, CIPANP2006, “Ds Scan and Confirmation of the Y(4260)”
D Hadronic Analysis: Q. He et al., Phys. Rev. Lett, 95, 121801 (2005) (57 pb-1) P. Onyisi, CHARM2006, “Hadronic Charm decay at CLEO-c” (281 pb-1)
Cabibbo-suppressed Decays: P. Rubin et al., Phys. Rev. Lett.96, 081802 (2005). Ds Inclusive & Exclusive: S. Stone, FPCP06, “Hadronic Charm Decays and D Mixing “ D+-+ Dalitz Analysis:
D. Cinabro, FPCP06 “Interference Effects in D Meson Decays” M. Dubrovin, CHARM2006, “Charm Dalitz Analyses from CLEO-c”
DK+K-0 Dalitz: C. Cawfield, et al, hep-ex/0606045, submitted to Phys. Rev. D D. Cinabro, FPCP06 “Interference Effects in D Meson Decays”
Many thanks to my CLEO collaborators, especially: P. Onyisi, A. Ryd, B. Lang, M. Dubrovin, H. Mahlke-Krueger
Steven Blusk, Syracuse University 16
Summary CLEO-c is hitting it stride already many measurements have surpassed world averages
Ds scan Ecm = 4160 MeV optimal for Ds physics Expect ~4-5X more DD and Ds
+Ds- data by mid-
2008.
Significant improvements on knowledge of D hadronic BF’s and many new modes being uncovered.
Critical improvements on golden modes Should have error on Beff(Ds) ~ 5%
Hadronic analyses have just begun… many more to come.
More (open charm) hadronic, semileptonic and leptonic results in this session and CKM/Rare decays session
Steven Blusk, Syracuse University 17
BACKUPS
Steven Blusk, Syracuse University 18
D Hadronic Overview
e+ e-
DD
D Reconstruction Techniques in CLEO-c Untagged analysis – reconstruct only one D meson in signal mode, use Bref
Tagged analysis Reconstruct 1 D meson in “clean” hadronic modes with “large” *B Use remaining charged particles & showers to reconstruct second D meson.
Hadronic (this talk) Semileptonic (see talk by Yongshen Gao in Session 10) Leptonic (see talk by Sheldon Stone in Session 10)
Use kinematic variables: E=Ebeam-ED
2 2bc beam DM E p
Steven Blusk, Syracuse University 19
Substructure in CS modes
Mbc-MD3
E Signal RegionE Sideband Region
+- 00
D++-0 Signal D++-0
Sideband
D++00
SignalD++00
Sideband
D++--0
SignalD++--0
Sideband
3.61 ± 0.25 ± 0.26 3.0 ± 0.6
< 0.34 (90% CL) ---
0.62 ± 0.14 ± 0.05 ---
< 0.26 (90% CL) ---
< 1.9 (90% CL) ---
1.7 ± 0.5 ± 0.2 ---
Mode CLEO-c PDG
Steven Blusk, Syracuse University 20
• Minimize Log likelihood
• Matrix element
• Partial waves (PWR):
– Spin-dependent BW for conventional resonances
– I=2 π+π+ S-wave
– π+π− S-waves:
–Oller
–Flatte
Dalitz Fit Details1
2 log ( , )N
n nn
L PDF x y
2( , ) | ( , ) | ( , ) (1 ) ( , )s BPDF x y f N M x y x y f N B x y
RiR R R R
reson
M a e PW F aR= amplitude, R = relative phasePWR = Mass & spin dependent partial wave functionR = Angular distributionFR = Blatt-Weiskopf angular momentum penetration factor
20 ( )2
2 00
( ) 1( )
2
i mIJ
m ea m
i
2 21( ) , where, (0.47 0.22) GeVA
A
Pole s s is s
For S-wave(s=m
2)
0
0
(890) 2 2 2 2
1( )
( )ff KK KK
Flatte mm m i g g
gab == coupling of f0 to abab=2pa/m (phase space factor)