Charm and QCD at CLEO-III and CLEO-c
Jim Napolitano (RPI & Cornell)
Physics topics: 0 − − + 1) Measurement of Ξc → pK K π (CLEO-III) 2) Form factors in D0 → {π−,K−}e+ν (CLEO-III ⇒ CLEO-c) 3) Disentangling glueballs and qq¯ states (CLEO-c)
XXXIX Rencontres de Moriond QCD and High Energy Hadronic Interactions 28 March - 04 April, 2004
1 2230902-007 10 9 CLEO Integrated Luminosities CLEO Physics (1D) 8 CLEO Upgrades 10 A CP Limits RICH CESR Upgrades B I New DD Mixing Tracking Limit B K* 2cm BP CLEO III bs Silicon 7 He-propane 10 B K 9x5 Bunches B K SC IR Quads ear CLEO II.V
Y B / SC RF I CsI 9x4 Bunches 3.5cm BP I BB / Crossing Angle 10 6 (BB Mixing) CLEO II 9X3 Bunches b u New Tracking 1 IR Ds CLEO I.V 5 b c 10 B Decay (4S), (5S) Microbeta CLEO I 7 Bunches Pretzel Orbits 10 4 1980 1985 1990 2 1995 2000 2005 CLEO III Solenoid 2230801-005 Coil RICH Calorimeter
Drift Chamber Muon SC and Chambers Rare Earth Quads Silicon Magnet Vertex Detector Iron
3 0 − − + 1) Measurement of Ξc → pK K π
See arXiv:hep-ex/0309020, to appear in Physical Review D
0 − ¯? 0 Physics: The decay Ξc → pK K (892) cannot proceed through external W decay, so it is “color suppressed”. ⇒ Want to separate it from nonresonant four-body decays.
0 − − + 0 − + Measured Ξc → pK K π rate relative to Ξc → Ξ π
Needs extensive p, K, π particle identification made possible by RICH in CLEO-III
Only previous result: ACCMOR 1990 (four events, all K¯ ?)
4 0 RESULTS: Ξc Decay
0 Ξc Decay modes 150 0990803-002 pK−K−π+ ) 2 100 K−π+ mass distribution: 50 Entries / 6 (MeV/c
0 2.30 2.40 2.50 2.60 I M(pK K I +) (GeV/c2) 100 0991203-003 Ξ−π+
) 75
2 0 − − + B(Ξc → pK K π )/ 0 − + 50 B(Ξc → Ξ π ) = 0.35±0.06±0.03
25 Entries / 6 (MeV/c B(Ξ0 → pK−K−π+; No K¯ ?)/ 0 c 2.30 2.40 2.50 2.60 0 − + M( I +) (GeV/c2) B(Ξc → Ξ π ) = 0.21±0.04±0.02
5 2) Form Factors in D0 → {π−,K−}e+ν
New CLEO-III analysis to be published soon.
2
dΓ G 2 µ µ + 2 3 2
For q ≡ p (W ) have = Vcq p F(q ) dq2 24π3
Note: First measurement of D → πeν form factor shape!
Plus: New result for B(D0 → πeν)/B(D0 → Keν)
6 Signal and Background in CLEO-III
0 ?+ + 0 Identify D from D → πslowD
Kinematic variable used is ∆M ≡ M(D?) − M(D)
D0 → K−e+ν D0 → π−e+ν 1500 400
300
1000
200
500
100
0 0 0.12 0.17 0.22 0.27 0.32 0.12 0.17 0.22 0.27 0.32 ∆M (GeV/c2) ∆M (GeV/c2)
⇒ The challenge for D → πeν is significant!
7 0 − + 2 RESULTS: D → π e νe Normalized q Distribution
All results are preliminary!!
Form factor models Binned data points 0.60
0.50
0.40 1 dΓ Γdq2 × 0.30
Effic. 0.20
0.10
LOW MID HIGH 0.00 q2 (GeV2/c2)
Plus: B(D0 → πeν)/B(D0 → Keν) = 0.097 ± 0.010 ± 0.010
8 2230104-002 CLEO-c Solenoid Coil Barrel Calorimeter Ring Imaging Cherenkov Detector Drift Chamber Inner Drift Chamber / SC Quadrupole Beampipe Pylon
Endcap SC Calorimeter Quadrupoles
Rare Earth Quadrupole Iron Polepiece
Magnet Barrel Muon Iron Chambers
9 The CLEO-c Program
¯ Prologue: Completed Υ(1S), Υ(2S), Υ(3S), Υ(5S), ΛbΛb runs, and short runs carried out at ψ0(3686), ψ00(3770),...
Dedicated Running in ∼1 Year Blocks
−1 Act I: ψ(3770) 3 fb ⇒ 30M Events (for σDD¯ = 10 nb) ⇒ 6M Tagged D decays
√ −1 Act II: s ≈ 4.1 GeV 3 fb ⇒ 300K Tagged Ds decays
Act III: J/ψ(3097) 1 fb−1 ⇒ 1 Billion J/ψ decays
Act I is already underway!
Epilogue: ψ0(3686), R, . . . depending on time and resources
10 CLEO-c event: e+e− → ψ00(3770) → D0D¯ 0 0 − + 0 + − D → K e νe D¯ → K π
11 Signal and Background for D0 → π−e+ν in CLEO-c
Monte Carlo Data (Preliminary!) Assumed 1 fb−1 Analyzed 60 pb−1 Particle ID cuts applied No particle ID cuts (yet) 0120601-002 600
0 I + D e D0 K eI + 500
400
300
200 Events / (0.005 GeV)
100
0 I I I 0.3 0.2 0.1 0 0.1 0.2 0.3 U = Emiss I Pmiss (GeV)
12 3) Disentangling Glueballs and qq¯ States
Radiative J/ψ decay is an excellent glueball filter J/ψ → γgg → γ + glueball
Lattice QCD says the lightest glueball is a scalar meson with a mass between 1500 and 1700 MeV/c2.
The quark model says there are two scalar mesons in this mass region (i.e. |uu¯ + dd¯i ≡ |nn¯i and |ss¯i).
Three states have been observed:
f0(1370), f0(1500), f0(1710)
⇒What is the mixture of qq¯ and glueball?
13 Mark-III (SPEAR): 6 × 106 J/ψ J/ψ → γX, where X → ...
2 2 2 2 |a0,0| |a2,0| |a2,1| |a2,2| 3000 (a) (b) (c) (a) 2000 1000 K K 1000 S S
0 0 (d) (e) (f) (b) 2000 K+K− 1000 1000 Events/(0.1 GeV) Events/(0.1 GeV) 0 0 (g) (h) (i) (c) 1000 π+π− 1000 500
0 0 1.0 1.5 2.0 1.2 1.6 2.0 1.2 1.6 2.0 1.2 1.6 2.0
6-96 Mass (GeV) 7236A5 6-96 Mass (GeV) 7236A6 Data Points: A Bin-by-Bin (i.e. Mass Independent) Fit Solid Lines: A Mass Dependent Fit to the Data Points
No sign of the f0(1500)?
14 Radiative Decays as a Probe of qq¯-Glueball Mixing F. E. Close, et al., Phys. Rev. D 67, 074031 (2003)
M(glueball) < M(nn¯) ≡“L” M(nn¯) < M(glueball) < M(ss¯) ≡“M” M(glueball) > M(ss¯) ≡“H”
Radiative Decay Widths in keV ΓTot f0 → γρ(770) f0 → γφ(1020) MeV State LMH LMH f0(1370) 443 1121 1540 8 9 32 ∼300 f0(1500) 2519 1458 476 9 60 454 109 f0(1710) 42 94 705 800 718 78 125 Excellent discrimination! −2 −4 ⇒ Expect B(f0 → γV ) ≈ 10 to 10 . −3 For B(J/ψ → γf0) ≈ 10 we should acquire 10, 000 to 100 events for 109 J/ψ.
15 Summary and Outlook
• CLEO-III is still producing results This Conference: M. Shepherd and J. Duboscq See also: M. Dubrovin, Moriond QCD 2003, including D → πππ, D → Kππ, D → KKπ,...
• CLEO-c well underway towards 3 fb−1 at ψ00(3770) Large sample of clean DD¯ pairs Hadronic and electroweak physics analyses started
• Strong future program for CLEO-c ¯ + − γDD and Ds Ds production Goal of 109 J/ψ events Other physics opportunities Stay Tuned! Thank you!
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