1. Recent Charm from CLEO Yongsheng Gao Southern Methodist University (CLEO Collaboration) HEP2003 Europhysics Conference Aachen, Germany July 17 ─ 23, 2003

2. Southern Methodist Univ.Yongsheng Gao 2 Outline Introduction Introduction Rare Charm Results from CLEO Rare Charm Results from CLEO D +   +  , K +  , K + K s D 0     +  0 Dalitz Analysis First Observation of D 0  K s   First Search for D 0    Future Outlook and CLEO-c Future Outlook and CLEO-c

3. Southern Methodist Univ.Yongsheng Gao 3 Why Rare Charm? Hunting Ground for New Physics Hunting Ground for New Physics – – Possible New Physics in box & loop – – SM background suppressed – – Precision measurements possible – – Clean samples already exist! D0 E791

4. Southern Methodist Univ.Yongsheng Gao 4 Charm Physics at CLEO > 360 Publications since 1980 Diverse physics topics Over 30% on Charm Physics

5. Southern Methodist Univ.Yongsheng Gao 5 CLEO Detector CLEO II (1989 – 1995): CLEO II (1989 – 1995): 4.7 fb -1 CLEO II.V (1995 – 1999): CLEO II.V (1995 – 1999): 9.0 fb -1 CLEO III (1999 – 2002): CLEO III (1999 – 2002): 16.0 fb -1 CLEO-c (2003 – 2008): > 7 CLEO-c (2003 – 2008): > 7 fb -1

6. Southern Methodist Univ.Yongsheng Gao 6 D +   +  , K +  , K + K s Study SU(3) Symmetry Breaking Study SU(3) Symmetry Breaking

7. Southern Methodist Univ.Yongsheng Gao 7 D +   +  , K +  , K + K s First Study

8. Southern Methodist Univ.Yongsheng Gao 8 D +   +  , K +  , K + K s ** Preliminary ** CLEO CONF 03-02 hep-ex/0306019 =1 in the limit of SU(3) >1 indicates destructive interference Between internal & external

9. Southern Methodist Univ.Yongsheng Gao 9 E791 D +     -  + Results Fit Frac. (%)     20.8 ± 2.433.6 ± 3.2 ± 2.2 f    7.4 ± 1.46.2 ± 1.3 ± 0.4 f    6.3 ± 1.919.4 ± 2.5 ± 0.4 f    10.7 ± 3.12.3 ± 1.5 ± 0.8     22.6 ±3.70.7 ± 0.7 ± 0.3 Non-res38.6± 9.77.8 ± 6.0 ± 2.7    46.3 ± 9.0 ± 2.1   138/162 Phys. Rev. Lett. 86: 770, 2001 Strong Evidence for σ (500)

10. Southern Methodist Univ.Yongsheng Gao 10 Dalitz Analysis of D 0  -  +  0 m 2 (     ) (GeV 2 ) m 2 (     ) (GeV 2 ) No contribution from  (500) at ~1% level m 2 (     ) (GeV 2 ) 0 1 2 3 m 2 (     ) (GeV 2 ) 0 1 2 3 m 2 (     ) (GeV 2 ) 0 1 2 3 AmplitudePhaseFit Fraction ++ 1 (fixed)0 (fixed)76.5±1.8±4.8 00 0.56±0.02±0.0710±3±323.9±1.8±4.6  0.65±0.03±0.04  4±3±4 32.3±2.1±2.2 NR1.03±0.17±0.3177±8±112.7±0.9±1.7 ** Preliminary ** CLEO CONF 03-03, hep-ex/0306048

11. Southern Methodist Univ.Yongsheng Gao 11 First Observation of D 0  K s  o CLEO’s K S     and BaBar’s K S K  K + Dalitz analyses, K S a 0 (980) seen in K S    , a 0 (980)  is dominant ** Preliminary **

12. Southern Methodist Univ.Yongsheng Gao 12 K S a 0 (980) is dominant K * (892)  is seen Something else is needed: NR, K S a 2 (1320), K S a 0 (1450) , K 0 (1430) , K 1 (1410)  …?? First Observation of D 0  K s  o ** Preliminary **

13. Southern Methodist Univ.Yongsheng Gao 13 First Search for D 0    SM Prediction:  10 -8 SM Prediction:  10 -8 Burdman, Golowich, Hewett, Pakvasa Phys. Rev. D66 014009 (2002) CLEO Results: PRL 90, 101801 (2003)

14. Southern Methodist Univ.Yongsheng Gao 14 What is CESR-c & CLEO-c? Run CESR/CLEO at Charm Threshold Run CESR/CLEO at Charm Threshold – – http://www.lns.cornell.edu/CLEO/CLEO-c/ – – National Science Board approved in Feb. 2003 – – CESR-c/CLEO-c has started in June of 2003

15. Southern Methodist Univ.Yongsheng Gao 15 CLEO-c Program 2004:  (3770) ~ 3 fb -1 30 million DD events, 6 million tagged D decays (310 times MARK III) 2005 : MeV ~ 3 fb -1 1.5 million D s D s events, 0.3 million tagged D s decays (480 times MARK III, 130 times BES) 2006:  (3100), ~1 fb -1 &  (3686) ~ 1 Billion J/  decays (170 times MARK III, 20 times BES II) ss L (10 32 cm -2 s -1 ) 3.1 GeV 2.0 3.77 GeV3.0 4.1 GeV3.6 Expected machine performance: performance: CLEO CCLLEEOOcCCLLEEOOc

16. Southern Methodist Univ.Yongsheng Gao 16 CLEO-c Future Outlook ReactionEnergy(MeV)L fb -1 PDGCLEO-c f Ds Ds+  Ds+   4140317%1.7% f Ds Ds+  Ds+   4140333%1.6% f D+ D+  D+   37703UL2.3% Decay  s L Double PDG CLEOc fb-1 tags (  B/B %) (  B/B %) D 0  K -  + 3770 3 53,000 2.4 0.6 D +  K -  +  + 3770 3 60,000 7.2 0.7 D s  4140 3 6,000 25 1.9 Search for Glueballs and Hybrids CLEO-c will take data in Oct of 2003 New collaborators are WELCOME!