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First Results from CLEO-c

First Results from CLEO-c. Thomas Coan. Southern Methodist University. CLEO Collaboration. CLEO-c Physics Program. D +  +   Decays. Absolute Br (D  hadrons). e + e -   (DD). Summary. CLEO-c Physics Focus. Heavy Flavor Physics: “overcome QCD roadblock”.

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First Results from CLEO-c

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  1. First Results from CLEO-c Thomas Coan Southern Methodist University CLEO Collaboration • CLEO-c Physics Program • D++  Decays • Absolute Br(D  hadrons) • e+e-  (DD) • Summary

  2. CLEO-c Physics Focus Heavy Flavor Physics: “overcome QCD roadblock” • CLEO-c: precision charm absolute Br measurements Leptonic decays  decay constants Semileptonic decays Vcd, Vcs, V_CKM unitarity check, form factors Absolute D Br’s normalize B physics Test QCD techniques in c sector, apply to b sector  improved Vub, Vcb, Vtd, Vts Physics beyond SM will have nonperturbative sectors • CLEO-c: precise measurements of quarkonia spectroscopy & • decay provide essential data to calibrate theory. Physics beyond SM: where is it? • CLEO-c: D-mixing, charm CPV, charm/tau rare decays.

  3. Why Charm Threshold? • Large production , low decay multiplicity • Pure initial state (DD): “no” fragmentation • Double tag events: “no” background • Clean neutrino reconstruction • Quantum coherence: • aids D-D mixing and CPV studies

  4. CLEO-c Run Plan 2004: y(3770) – 3 fb-1 18M DD events, w/ 3.6M tagged D decays (150 times MARK III) 2005: s  4100 MeV – 3 fb-1 1.5M DsDs events, w/ 0.3M tagged Ds decays (480 times MARK III, 130 times BES) 2006: y(3100) – 1 fb-1 1 Billion J/y decays (170 times MARK III, 15 times BES II)

  5. Tagging Technology • Pure DD/DsDs production: (3770)  DD • s ~4140  DsDs • Large branching fractions (~1-15%) • High reconstruction efficiency •  High net tagging efficiency ~20% MC MC M(D)

  6. Absolute Br’s w/ Double Tags ~ Zero bkgnd in hadronic modes w/ D0 tag D0 K w/ D tag D K MC MC M(D) (GeV/c2) w/ 3 fb1 Mode s (GeV) PDG2kCLEOc (dB/B %) (dB/B%) D0K-p+ 3770 2.40.6 D+  K- p+p+ 3770 7.20.7 Ds fp 4140 251.9

  7. |VCKM|2 |fD|2 l n fDq from Leptonic Decays  ( Dq  l  )  f_Dq2 V_cq2 MC KL Ds+ mn  D+ mn w/ 3 fb-1 & 3-gen CKM unitarity: Decay Constant Reaction PDG f/f CLEO-c f/f f Ds Ds+ mn 12% 1.9% f Ds Ds+ n 33% 1.6% f D D+ mn ~50% 2.3%

  8. Br ( D P l  ) / D =  = V_cq2 |VCKM|2 d ( D P l  ) / dq2 V_cq2 f(q2)2 |f(q2)|2 Semileptonic Decays MC MC 1 fb-1 1 fb-1 D0 p l n Measuref(q2)2 Kl q2 (GeV2) U=E_miss  P_miss Mode PDG04 (B/B%) CLEOc (B/B%)  Vcd/Vcd & Vcs/Vcs 1.6% Vcd/Vcd = 5.4% (PDG04) Vcs/Vcs = 9.3% (PDG04) 3 D0 K ln 0.4 D0 pln 16 1.0 D pln 48 2.0 Ds   ln 25 3.1

  9. c X c ¯  Probing QCD • Gluons carry color charge  binding: Glueballs = gg  and Hybrids = qqg  • Radiative  decays: ideal glue factory • CLEO-c: 10 J/ decays   60M J/  X Partial Wave Analysis MC Absolute Br’s: , KK, pp, , ...  + • E.g.: fJ(2220) CLEO-c: find/debunk fJ(2220) MC MC  K K+

  10. CLEO-c Detector 93% of 4p sE/E = 2% @1GeV = 4% @100MeV B=1.0 T 83% of 4p 87% Kaon ID with 0.2% p fake @0.9GeV 93% of 4p sp/p = 0.3% @1GeV dE/dx: 5.7% p @minI Data Acquisition: Event size = 25kB Thruput  6MB/s Trigger : Tracks & Showers Pipelined Latency = 2.5 ms 85% of 4p p>1 GeV

  11. 2 l Weak Physics Strong Physics (1 - ) 2 GF m_Dqm 2 m_Dq 2 l 8 2 2 m f_Dq|Vcq| _Dq Leptonic Decays: D+  +  Br(Dq l) = Seek to measure fD+ • fD+ provides “iron post of observation” for Lattice QCD • fD+ useful for checking potential models • “Calibrated” Lattice QCD (fB/fD) + fD  fB • fB + B-mixing m’ments  |Vtd/Vts| precision

  12. 2 2 • MD = Ebeam ( pi)2   • MM2= (Ebeam E)2  ( pD  p )2 Single D Tag e+e (3770)   D+D Signal side D-Tag side  • L dt = 57 pb1 @s =  D  K+,K+, Ks, Ks, Ks • D tag side: • /K ID: dE/dx + RICH • 0 recon:  shower shape/location in CsI • Ksrecon:  kinematic fit to displaced vertex • Signal side: • 1 track from event vertex, min_I in CsI • “small” (< 250 MeV) neutral E in CsI • no reconstructed Ks • Key analysis variables:

  13. MD Distribution v. D Tag Data Data K+0 K+ Data Data Ks Ks+ Data Ks S: 28575  286 B: 8765  784

  14. (MM2)  0.025 GeV2 MM2 Distribution v. D Tag MC MC MC MC MC

  15. Check MC (MM2) w/ data: D  Ks Data  Ks++ Tag  Leptonic Decays: Signal Region   0.0240.002 GeV2 Scale MC (MM2) w/ data:  = (0.024/0.021)0.025 = 0.028 GeV2   0.0210.001 GeV2 8 evts D+  K0+

  16. Mode # of Events 0.31  0.04 0.06  0.05 0.36  0.08 Nsig Ntag negligible D+  + Br(D+  + = (3.5  1.4  0.6) x 104 D+  K+ D+  + • D0D0Background: 0.16  0.16 events fD+ = (201  41  17) MeV D+  + Background + Results Background estimates via MC • D Background: • e+e  continuum: 0.17  0.17 events  O’all Bkg: 1.07  0.25 events  1.07  1.07 events &  = 69.9% for D+ + recon. Br(D+  + = Preliminary

  17. 1 2D B = 2 S 2 w/ 2  1 : S2 D0 D0 NDD =  (DD) = 4D S2 4DL Br(D) & (DD) M’ment @ s = (3770) K+ X Single Tag Double Tag    e+ e e+ e   D0 D0 K K + + S = 2NDD B1 D = NDD B22 i.e., B &  independent

  18. Determine 5 Br’s and (e+e  D0D0) & (e+e  D+D) 2  • MBC = (Ebeam ( pi)2) Single and Double Tags • 10 Single Tag + 13 Double Tag modes D0 K+,K+0, K++ + c.c. D+ K++,Ks+ + c.c. • Event selection similar to fD+ analysis • Key analysis variables: • E= Ebeam Ei

  19. D and D fit together: same signal param’s, indep. bkg. MC Single and Double Tag Yields • N(single tags) from ML fit to M_BC • Line shape parameters from MC D0  K+ D0  K+ Data • N(double tags) from 2-D ML fit to 2-D M_BC K+0 v. K+0 Data

  20. Br(D+ K++), Br(D+  Ks+) and N(D0D0), N(D+D) Fit Results for Br(D) and (DD) • 2 fit to account for correlations btwn single/double tags, bkg • Fit Output: Br(D0 K+) , Br(D0 K+0), Br(D0 K++) • Fit Input: S.T. & D.T. yields, _tag, _bkg + errors • 2/ndof = 9.0/16, C.L. = 91.4% CLEO-c Preliminary PDG04 Br(D0  K+) = 0.039  ?  ? Br(D0  K+0) = 0.130  ?  ? Need pdg comp Br(D0  K++) = 0.081  ?  ? Br(D+  K++) = 0.098  ?  ? Br(D+  Ks +) = 0.016  ?  ? N(D0D0) = 1.98 x105 (D0D0) = 3.47  0.07  0.15 nb N(D+D) = 1.48 x105 (D+D) = 2.50  0.11  0.11 nb (DD) = 6.06  0.13  0.22 nb

  21. Summary I need nicer plots for Br(D  hadrons)

  22. Backup

  23. 1.5 T  1.0T 83% of 4p 87% Kaon ID with 0.2% p fake @0.9GeV 93% of 4p sp/p = 0.35% @1GeV dE/dx: 5.7% p @minI 93% of 4p sE/E = 2% @1GeV = 4% @100MeV CLEO III Detector  CLEO-c Detector Trigger : Tracks & Showers Pipelined Latency = 2.5 ms Data Acquisition: Event size = 25kB Thruput  6MB/s 85% of 4p p>1 GeV

  24. J/   X Inclusive  - Spectrum MC • Inclusive  -spectrum • Search for monochromatic  • E.g., 24% efficient for fJ(2220) • 10 sensitivity for narrow resonances • Modern 4 detector • Suppress hadronic bkgnd: J/X • Huge data set • Plus  and (1S) data Determine JPC and gluonic content

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