1. Zijin Guo Univ. of Hawaii Representing BES Collaboration J/    pp and  BES Beijing, China

2. The BES Detector TOF EM Shwr counter

3. World J/  and  (2S) Samples (10 6 ) J/   (2S)

4. A narrow pp enhancement near M pp  2m p in J/    pp

5. NN bound states (baryonium)?? + n+  deuteron: loosely bound 3-q 3-q color singlets with M d = 2m p -  baryonium: loosely bound 3-q 3-q color singlets with M b = 2m p -  ? attractive nuclear force attractive force?? There is lots & lots of literature about this possibility

6. pp  e + e  Bardin etal e + e   hadrons FENICE e+e6e+e6 2m p Fit: M = 1870 ± 10 MeV  = 10 ± 5 MeV R. Calabrese PEP-N work-shop proceedings DM2 unpub. Is there a narrow J PC =1  pp system near M pp = 2m p ?

7. study pp from J/    pp C-parity = + S (P?)-wave (for M pp  2m p )  probes J PC = 0  (0  ?) states complements pp  e  e  and e  e  annihilation unpolluted (by other hadrons) environment

8. Use BESII’s 58M J/  decays J/    pp Select J/    pp 4-C kinematic fit dE/dx for proton id non-pp bkg small main bkg from J/     pp ???? J/    c  c   pp (calibration reaction)

9. Fit signal with an S(P)-wave BW q = daughter momentum q 0 = daughter momentum @ peak keep constant threshold factor

10. Fit to data M=1859 MeV/c 2  < 30 MeV/c 2 (90% CL) J/    pp M(pp)-2m p (GeV) 00.10.20.3 3-body phase space acceptance  2 /dof=56/56 fitted peak location acceptance weighted BW +3 +5  10  25

11. P-wave fit?? M=1876 ± 3 MeV  < 30 MeV (90% CL)  2 /dof=59/56 OK! M=2m p

12. cos   distribution 1+cos 2   (expected for J/     ) sin 2   M(pp)<1.9 GeV

13. Summary (I) if what we see is an S-wave resonance: M=1859 MeV/c 2  < 30 MeV/c 2 (90% CL) +3 +5  10  25 A narrow pp enhancement near M pp  2m p in J/    pp

14. not consistent with any PDG meson state peak below, but near 2m p : baryonium? narrow width: why so long-lived? similar patterns seen in baryon-antibaryon systems produced in B meson decays –B  ppK B  ppD B  p  B  p  c 

15. Strange & charmed systems B   p   M(  p)  (GeV) BpcBpc M(  c  p)  (GeV) (in these cases, the peaking doesn’t seem to be right at threshold)

16. Partial Wave Analysis of J/    KK

17. Lattice QCD: the ground state scalar glueball should be in the mass range 1.5 – 1.7 GeV Long history of uncertainty about f 0 (1710) J /    K + K - and  K S K S are very important to investigate the f 0 (1710)

18. Data and Analysis Method Perform separate amplitude analyses for J/    K + K -  K S K S Amplitudes are fit to relativistic covariant tensor expressions (mass range 1-2 GeV) The maximum likelihood method is employed Bin-by-bin fit: the data are analyzed independently in each mass bin (40MeV) Global fit: Breit-Wigner structures + mass, width scan + lnL comparison

19. The K + K - and K S K S mass distributions from J/  radiative decay after acceptance and isospin corrections

20. J/    f’ 2 (1525)  f 0 (1710)  f 2 (1270)  f 0 (1500)  +broad 0 ++ and 2 ++ Components used in the PWA fit

21. Bin-by-bin fit Global fit Amplitude intensity

22. Summary (II) Using BESII data, partial wave analyses were done on the K + K - and K S K S systems produced in J/  radiative decay for the mass range 1-2 GeV KK D- wave intensity shows a clear f’ 2 (1525) signal and the helicity amplitude ratios x,y appear to be consistent with the theoretical prediction

23. Strong production of f 0 (1710) M = 1740±4± 10 MeV Г = 166 +5+15 MeV (Global fit) The non-flat angular distribution in the KK mass region ~1.7 GeV is due to the interference between S- wave and weak D- wave amplitudes Bin-by-bin fit and global fit give very consistent analysis results 25 -8-8 - 10

24. Results Bin-by-bin Global

25. Systematic Error global fit

26. Study J/    0 pp bkg with MC & data J/    0 pp (data) three-body phase space Monte Carlo J/    0 pp   pp (MC) M(pp)-2m p (GeV) no peak!!

27. Is M peak really less than 2m p ? No turnover at threshold  peak mass must be <2m p weight events by q 0 /q: (i.e remove threshold factor) M(pp)-2m p (GeV)

28. mass determination bias threshold observed peak BW “peak” below-threshold mass & widths measurements can be biased when there is background

29. could it be a tail of a known resonance? 0  resonances in PDG tables:  (1760) M=1760  = 60 MeV  (1800) M=1801  = 210 MeV  2 /dof=323/58  2 /dof=412/58

30. Coulomb effect? coulomb factor phase-space term

31. BW vs Coulomb