1. Recent Results on  (2S) and  cJ Decays from BES Zhiyong Wang IHEP, Beijing,China for the BES Collaboration VietNam 2004 5th Rencontres du Vietnam Particle Physics and Astrophysics Hanoi August 5 to August 11, 2004

2. BESII Detector VC:  xy = 100  m TOF:  T = 180 ps  counter:  r  = 3 cm MDC:  xy = 220  m BSC:  E/  E= 22 %  z = 5.5 cm  dE/dx = 8.5 %   = 7.9 mr B field: 0.4 T  p/p=1.7%  (1+p 2 )  z = 3.1 cm

3. BESII obtained 14 M  ’ events Nov.01-Mar.02   ’  VP   ’  VT   ’  PP (K 0 S K 0 L )    J/  -contained   cJ   , pp, f 0 f 0  Other  ’ and  cJ decays 3M 14M

4.  pQCD rule (12% rule) [the relation between J/  and  ’ ]  Violation was revealed by MARK-II, confirmed by BES at higher sensitivity.  Provide information for understanding the charmonium decay dynamics. “pQCD rule” and “  puzzle” K*K ρπ MARK-II

5. The Relative Phase J/ψ Decays: 1. AP: 90 ° M. Suzuki, PRD63, 054021 (2001) 2. VP: (106 ±10) ° J. Jousset et al., PRD41, 1389 (1990) D. Coffman et al., PRD38, 2695 (1988) N. N. Achasov, talk at Hadron2001 3. PP: (90 ±10) ° M. Suzuki, PRD60, 051501 (1999) 4. VV: (138 ±37) ° L. Köpke and N. Wermes, Phys. Rep. 74, 67 (1989) 5. NN: (89 ±15) ° R. Baldini et al., PLB444, 111 (1998) ψ’  VP 1. φ=180 ° (90 ° ruled out!) M. Suzuki, PRD63, 054021 (2001) 2. φ= ﹣ 90 ° or φ=180 ° (with continuum amplitude) P. Wang, C. Z. Yuan and X. H. Mo, PRD69, 057502 (2004) φ

6. Measure the relative phase in e + e – experiment phase Take the continuum contribution and its interference effect into consideration, we could determine not only the magnitude but also the sign of the phase. φ interference

7.   ’  VP K *+ K - +c.c., K *0 K 0 +c.c.,  0   ’  VT  f 2,  a 2, K * K * 2,  f 2 '   ’  PP K 0 S K 0 L (also J/  decays) In this talk, I will cover for pQCD rule and phase study!

8.  ’  VP K * (892)K+c.c. K*  K * 2 (1430) B.G. K *0 9.6±4.2 evts, 3.5σ 65.6±9.0 evts, 11σ Br ± =(2.9±1.3 ±0.4)  10 –5 Br 0 =(15.0±2.1 ±1.9)  10 –5 K*  K *0 K * 2 (1430) B.G. BES preliminary! First observation! Large Isospin violation!

9.  ’  VP  0 B.G.  0 B.G.  0 @3.686GeV& L =(19.72 ±0.86) pb  1 @3.650GeV& L =(6.42 ±0.24) pb  1 Expects 22 continuum background events in  ’ sample! 31.2 ±7.2 evts. 7.4 ±2.8 evts. BES preliminary! Information on continuum data is very important for  ’ analyses!

10. VP Mode B(  ’  X )(10 – 5 ) B (J/  X )(10 – 4 ) (PDG2002) Q h ( % )  0 1.84  0.64  0.274.2  0.64.4  1.8 K *0 K 0 +c.c. 15.0±2.1±1.942±43.6±0.8 K* + K – +c.c. 2.9±1.3±0.450±40.58±0.27  BES-II results (Preliminary) 12% rule  ’  V P Suppressed !! Large isospin violation indicates EM decay important!

11.  ’  V T  f 2   +  –  0  +  –  a 2        K * K * 2  K  K   f 2 '  KK KK  +  –  +  –  0   K + K –  +  –  ’’  +  –  +  –  0   K + K – K + K –

12. f 2 (1270) B.G.(M.C.) B.G.(  )  ’  V T B.G. a 2 (1320) B.G. K * 2 (1430) K * (892) B.G. f 2 ' (1525) f 0 (980)

13. † This value from DM2 only Suppressed!! 12 % rule ( pQCD rule )  ’  V T VT mode B  ’  X (10 – 4 ) (BES-II) B J/  X (10 – 3 ) (PDG2002) Q h (%)  f 2 2.05± 0.41 ± 0.384.3±0.64.8±1.5  a 2 2.55± 0.73± 0.4710.9±2.22.3±1.1 K * K * 2 1.86± 0.32 ± 0.436.7±2.62.8±1.3  f 2 ' 0.44 ± 0.12 ± 0.111.23±0.21 † 3.6±1.5 PRD69, 072001 (2004)

14. Ks mass sidebands Bkg MC signal 14M ψ(2S)  ’  K S K L PRL 92, 052001 (2004)

15. Ks mass sidebands MC Bkg K* 0 K S +c.c. signal 58M J/ψ J/   K S K L PRD 69, 012003 (2004)

16. B (  ’  K S K L ) =5.24  10 – 5 Yuan, Wang, Mo: PLB567 (2003)73 K + K – &  +    inputs ; Input 1:DASP; Input 2:BESI ; Input 3: K + K – from BESI &  +   by form factor.  ’  K S K L –(82  29)°(121  27) ° First measurement of the phase in  ’ decays!

17. B  ’  Ks K L = (5.24± 0.47 ± 0.48 )  10 – 5 B J/   Ks K L = (1.82 ± 0.04 ± 0.13 )  10 – 4 B(  ’) enhanced! J/ ,  ’  K S K L

18.  ’  J/  -Contained Motivation: Improve Exp. Precision and Test Theory Calculation Inclusive Method [BES-I] XJ/ , J/   +  – ---------------------------------------------------------- Anything J/   0  0 J/   J/    c1,  c1  J/    c2,  c2  J/  Exclusive Method [BES-II]  J/ , J/  l + l – -----------------------------------------------------  0 J/   J/    c1,  c1  J/    c2,  c2  J/  Phys.Rev.D70:012003,2004Phys.Rev.D70:012006,2004

19. BES measures the BRs in high precision!   c2   c1  J/   o J/  First measurement B(  ´  0  0 J/  )=(18.2± 1.2)% XJ/  BE S

20.  ’    J/  Discussions PCAC [G. A. Miller, Phys. Rep. 194,1(1990)]: R<0.0098 R  <0.0065 BES result:R=0.048±0.007 QCD Multipole Expansion & BTG potential model [Y. P. Kuang, PRD24, 2874(1981), ibid. 37, 1210(1988) BES (+PDG for  ) : Casalbuoni et al: improved expression [PLB 309,163(1993)]

21. Λ signal in πp mass Clear Λ Λ-bar Signal Data Monte Carlo

22. Fit the mass spectrum χ c0 χ c1 χ c2 MC efficiencies ΛΛ-bar Mass (GeV)

23.  c0  c2  c1 Final states: γpp-bar PRD69, 092001(2004)

24.  c0  c0  f 0 (980) f 0 (980)  c2 KsKs No  c2  f 0 (980) f 0 (980)  Evidence for  c0  f 0 f 0 preliminary!

25. f 0 (980) recoil mass (m  =0.93-1.03 GeV) f 0 (980) side bands events recoil mass Two entries/event  c0  f 0 (980) f 0 (980) Strong evidence for  c0  f 0 (980) f 0 (980) 4.6  B(  c0  f 0 f 0, f 0   +  - ) =(7.5±1.9±1.7) ×10 -4 preliminary!

26. Final states with K S K S in  ’ decays From 14M  ’ (preliminary!) Many channels are first observation, useful for comparing with Isospin conjugate final states!

27.   ’  VP channels K * K and  are first observed. Large isospin violation effect in K * K mode. BES confirms the VP suppression in  ’ decays.   ’  VT channels  f 2,  a 2, K * K * 2 and  f 2 ' are first observed and branching ratios are measured. All are suppressed in  ’ decays.  First observation of K 0 S K 0 L in  ’ decay. Improved measurement of J/ψ  K 0 S K 0 L.  ’ is enhanced relative to the pQCD 12% rule.  ’  J/  -contained final states are to improve experimental precision and test theoretical predications.   cJ  , f 0 f 0 and p p are measured and  cJ  , f 0 f 0 are first observed.  Other  ’ and  cJ decays are also measured and some of them are first observed Summary

28. Thanks a lot ! 谢谢!