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

2. 2 CLEO-c Physics Focus Heavy Flavor Physics: “overcome QCD roadblock” 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: where is it? CLEO-c: D-mixing, charm CPV, charm/tau rare decays. CLEO-c: precision charm absolute Br measurements CLEO-c: precise measurements of quarkonia spectroscopy & decay provide essential data to calibrate theory. Physics beyond SM will have nonperturbative sectors

3. 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. 4 CLEO-c Run Plan 2004:  (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 D s D s events, w/ 0.3M tagged D s decays (480 times MARK III, 130 times BES) 2006:  (3100) – 1 fb -1 1 Billion J/  decays (170 times MARK III, 15 times BES II)

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

6. 6 Absolute Br’s w/ Double Tags ~ Zero bkgnd in hadronic modes Mode  s (GeV)PDG2k CLEOc (  B/B %) (  B/B %) D 0  K -  + 3770 2.4 0.6 D +  K -  +  + 3770 7.2 0.7 D s  4140 25 1.9 MC M(D) (GeV/c 2 ) D 0  K    D   K      w/ 3 fb  1 w/ D 0  tag w/ D   tag

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

8. 8 Semileptonic Decays |V CKM | 2 |f(q 2 )| 2 =  =  V_cq  2 Br ( D  P l ) /  D  V_cq  2  f(q 2 )  2 d  ( D  P l ) / dq 2 MC D 0   l  Kl U=E_miss  P_miss 1 fb-1 q 2 (GeV 2 ) Measure  f(q 2 )  2 D 0   l D    l D 0  K l Ds   l Mode PDG04 (  B/B%)CLEOc (  B/B%) 16 3 0.4 48 25 1.0 2.0 3.1   V cd /V cd &  V cs /V cs  1.6%  V cd /V cd = 5.4% (PDG04)  V cs /V cs = 9.3% (PDG04)

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

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

11. 11 Leptonic Decays: D +   +  Br(D q  l ) = m 2l2l 2 m_D q ( 1 - ) f_D q |V cq |  _D q 2 2 2l2l 88 GFGF 2 m_D q m Strong Physics Weak Physics f D+ provides “iron post of observation” for Lattice QCD “Calibrated” Lattice QCD (f B /f D ) + f D  f B f D+ useful for checking potential models Seek to measure f D+ f B + B-mixing m’ments  |V td /V ts | precision

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

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

14. 14 MM 2 Distribution v. D Tag MC  (MM 2 )  0.025 GeV 2

15. 15 Leptonic Decays: Signal Region  Data K s    +  + Tag  8 evts   0.024  0.002 GeV 2   0.021  0.001 GeV 2 D   K s   Check MC  (MM 2 ) w/ data: D +  K 0  +  Scale MC  (MM 2 ) w/ data:  = (0.024/0.021)  0.025 = 0.028 GeV 2

16. 16 Background + Results Br(D +   +  =  N tag N sig Br(D +   +  = (3.5  1.4  0.6) x 10  4 f D+ = (201  41  17) MeV  D  Background: Mode# of Events D +   +   D +  K   + D +   + D +     + 0.31  0.04 0.06  0.05 0.36  0.08 negligible  D 0 D 0 Background: 0.16  0.16 events Background estimates via MC  e + e   continuum: 0.17  0.17 events  O’all Bkg: 1.07  0.25 events  1.07  1.07 events Preliminary &  = 69.9% for D +  + recon.

17. 17 Br(D) &  (DD) M’ment @  s =  (3770)   KK ++ ee e+e+ X D0D0 D0D0   KK ++ ee e+e+ D0D0 D0D0 K+K+  Single TagDouble Tag S = 2N DD B  1 D = N DD B 2  2 w/  2   1 : 2 N DD = S2S2 4D S2S2 4DL   (DD) = i.e., B &  independent B = 2D S 11 22

18. 18 Single and Double Tags D 0  K   +, K   +  0, K   +    + + c.c. D +  K   +  +, K s  + + c.c.  Determine 5 Br’s and  (e + e   D 0 D 0 ) &  (e + e   D + D  )  10 Single Tag + 13 Double Tag modes  Event selection similar to f D+ analysis  Key analysis variables:   E = E beam   E i   M BC =  (E beam  (  p i ) 2 ) 2

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

20. 20 Fit Results for Br(D) and  (DD) Fit Input: S.T. & D.T. yields,  _tag,  _bkg + errors  2 /ndof = 9.0/16, C.L. = 91.4%  2 fit to account for correlations btwn single/double tags, bkg Fit Output: Br(D 0  K   + ), Br(D 0  K   +  0 ), Br(D 0  K   +    + ) Br(D +  K   +  + ), Br(D +  K s  +) and N(D 0 D 0 ), N(D + D  ) Br(D0  K  +) = 0.039  ?  ? Br(D0  K  +  0) = 0.130  ?  ? Br(D0  K  +  +) = 0.081  ?  ? Br(D+  K  +  +) = 0.098  ?  ? PDG04 CLEO-c Preliminary N(D0D0) = 1.98 x10 5   (D0D0) = 3.47  0.07  0.15 nb N(D+D  ) = 1.48 x10 5   (D+D  ) = 2.50  0.11  0.11 nb Br(D+  Ks  +) = 0.016  ?  ?  (DD) = 6.06  0.13  0.22 nb Need pdg comp

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

22. 22 Backup

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

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