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Qiang Zhao Institute of High Energy Physics, CAS, P.R. China

June 16, 2005. The scalar glueball production in J/  hadronic decays. Qiang Zhao Institute of High Energy Physics, CAS, P.R. China & Department of Physics, University of Surrey, Guildford, U.K. Place for “Glueball” in the meson spectroscopy

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Qiang Zhao Institute of High Energy Physics, CAS, P.R. China

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  1. June 16, 2005 The scalar glueball production in J/ hadronic decays Qiang Zhao Institute of High Energy Physics, CAS, P.R. China & Department of Physics, University of Surrey, Guildford, U.K. Place for “Glueball” in the meson spectroscopy “Puzzles” from the recent BES data for scalar mesons Glueball and QQ* mixings in the scalar mesons Mechanisms for scalar meson production in J/V f0  V PP ( V= , ; P = , , , K) Summary In collaboration with Frank Close (Oxford)

  2. Meson spectroscopy I) QQ* mesons Quarks as building blocks of hadrons: meson (qq*), baryon (qqq) Convention (Particle Data Group): 1) Quark has spin 1/2 and baryon number 1/3; 2) Quark has positive parity and antiquark has negative parity; 3) The flavor of a quark has the same sign as its charge.

  3. QQ* mesons: • Mesons are bound state of QQ* with baryon number B=0; • The parity is given by P=(1)L+1with orbital angular momentum L; • The meson spin J is given by |LS| < J < | L+S| , where S=0, 1 are • the total spin of the quarks. • 4. Charge conjugate is defined as C=(1)L+S for mesons made of quark • and its own antiquark. For light quarks: u, d, and s, the SU(3) flavor symmetry constrains the number of flavor QQ* multiplet: 3  3* = 8  1 3 4 1 1

  4. II) Non-QQ* mesons Type (a): JPC are not allowed by QQ* configuration For states in natural spin-parity series P=(1)L+1 =(1)J , the state must have S=1 and hence CP=(1)(L+S)+(L+1) =+1. Therefore, mesons with natural spin-parity but CP= 1 will be forbidden, e.g. 0+, 1+, 2+, 3+, … L + Natural: 0++, 1, 2++, 3, … Unnatural: ( 0), 1++, 2,3++, …  S=1 L + Unnatural: 0+, 1+, 2+, 3+, …  S=0

  5. Type (b): Mesons have the same JPC as a QQ*, but cannot be accommodated into the SU(3) nonet: 3  3* = 8  1 3 4 1 1 Mass f0(1710) Glueball ? QQ*-glue mixing ? f0(1500) f0(1370) (1020) (958) f0(980) Multiquarks ? (782) /f0(600) (547) 0 1 0 I=0

  6. Glueball: Mesons are made of colored gluons confined by strong interaction  g M J/ g R=G f0 Lattice 0++: 1.5 ~ 1.7 GeV Exp. Scalars: f0(1370) f0(1500) f0(1710) f0(1790) (?) Lattic QCD prediction Morningstar and Peardon, PRD60, 034509 (1999)

  7. “Puzzles” in the recent experimental data for scalar mesons • Beijing Spectrometer (BES) • e+ e-  J/  V f0  V PP, • V=, ; PP=, , , KK* • WA102 at CERN • p p  p p f0  pp PP

  8. f0(1370) at BES • f0(1370)clearly seen in J/  , but not seen in J/  . f0(1370) NO f0(1370) S. Jin, Plenary talk at ICHEP04

  9. f0(1710) at BES • Clear f0(1710) peak in J/  KK. • Nof0(1710) observed in J/   ! f0(1710) NO f0(1710) S. Jin, Plenary talk at ICHEP04

  10. Unusual beahvior of f0(1370), f0(1500) and f0(1710) prod. BES exp. for J/V f0VPP : i) f0(1370) has been seen clearly in J/ f0(1370), but not in J/; stronger f0(1370) coupling? ii) f0(1500) have not been directly see in J/KK*, , KK*, ; Why suppressed here? iii) f0(1710) is observed clearly in J/KK* and KK*, but not in , . Also, br(J/ KK*) ~6 br(J/KK*). stronger f0(1710) coupling? WA102 exp. for p p  pf ( f0) ps; f0  PP: i) f0(1370)  is dominant over KK*, , ; nonstrange nn* ii) f0(1500) was seen in all channels, and dominated by ; mixture of nn*, ss*, and gg ? iii) f0(1710) KK* is dominant. ss*

  11. Glueball and QQ* mixing in the scalar mesons In the basis of |G> = gg, |S> = ss*, and |N> = nn* = (uu*+dd*)/2, the glueball-quarkonia mixing can be expressed as: S G N The f0 states: Close, et al., PLB353, 385(1995); PRD53, 295(1996); PLB483, 345(2000).

  12. Parameterization of f0  PP r3 g0 r2 g0 g0 P   f0 P Partial decay widths for f0  PP: Close and Zhao, PRD71, 094022(2005)

  13. Experimental data from WA102 Unitarity constraints:

  14. f0 states 1710 S 1500 G 1370 N Lattice QCD: MG ~ 1.5 – 1.7 GeV - flavour mixing: = 8 cos - 1 sin = |S> - |N> = 8 sin + 1 cos = |S> + |N>

  15. f0 mixing matrix determined in f0  PP gg ss* nn*  KK* Satisfies: i) f0(1370)  is dominant over KK*, , ; nonstrange nn* ii) f0(1500) was seen in all channels, and dominated by ; mixture of nn*, ss*, and gg iii) f0(1710) KK* is dominant. ss*

  16. Scalar mesons production in J/  V f0 II) Doubly disconnected diagram I) Singly disconnected diagram  (ss*) g  (ss*) c c g J/ J/ f0 (ss*) c* f0 (nn*) c* III) Glue configuration pQCD Okubo-Zweig-Iizuka (OZI) rule: I) ~III) ~   II) =g2/4 ~ 0.3 However …  (ss*) c J/ f0 (gg) c*

  17. Implications of the OZI rule: gg ss* nn*  KK* i) OZI rule on f0(1370): br(J/ f0(1370)KK*)<< br(J/ f0(1370)) Exp: br(J/ f0(1370)) is dominant ! ii) OZI rule on f0(1710): br(J/ f0(1710)KK*) > br(J/ f0(1710)KK*) Exp: br(J/ f0(1710)KK*) / br(J/ f0(1710)KK*) ~ 0.3 !

  18. Factorization of J/  V f0  V P P V (, ) Transition amplitudes via potential V J/ P f0 III) I) II) P OZI-suppressed Doubly disconnected Project to the final physical states: Gluon-counting rule: I) ~ III)

  19. I) Singly disconnected diagram II) Doubly disconnected diagram (ss*), (nn*) • (ss*), (nn*) g c c g J/ J/ f0(ss*), (nn*) c* f0(nn*), (ss*) c* III) Glue configuration Gluon-counting rule: I) ~ III) (ss*) (nn*) c J/ f0(gg) c*

  20. Partial decay width for J/  V f0  V P P (nn*) (ss*) c c J/ J/ G(gg) G(gg) c* c* Flavor-blindness of quark-gluon interaction:

  21. Step 1: Direct test of the OZI rule BES Experiment: br(J/ f0(1710)KK*) = (2.0  0.7)  104 br(J/ f0(1710)KK*) = (13.2  2.6)  104 a) OZI rule applies: r  0 PDG estimate: Rexp = 0.75 b) OZI rule violated: r ~ 1 where r = 2.2

  22. Step 2: Normalize the G production Normalized glueball production br. ratios Scalar decay br. ratios

  23. Step 3: Theoretical predictions for J/V f0  V KK*, V  The “puzzle” can be naturally accounted for in the glueball-QQ* mixing scheme. Puzzle  Evidence for scalar glueball-QQ* mixings

  24. Further test of the gluon-QQ*mixings 1 billion J/ events from BES gg ss* nn* • f0    • probe the quark components of the scalars: • f0(1370) : f0(1500) : f0(1710) ~ 12 : 2 : 1 • ii) J/   f0 • f0(1710) > f0(1500) > f0(1370) • iii) f0   V, (V= , 0) • f0(1710)  ( ) > ( 0) • f0(1370)  ( ) < ( 0) • f0(1500)  ( ) < ( 0) • iv) Constrain the doubly OZI violation processes gg ss* nn*

  25. Summary I. The glueball contents are essentially important for interpreting the “puzzling” data from BES for the scalar meson production in J/ decays. II. The strong glueball-QQ* mixing implies the failure of the OZI rule in J/  V f0, and suggests the crucial role played by the doubly disconnected processes. III. A normalization of the glueball production rate is obtained, which possesses predictive power for the study of the glueball mixing effects in the J/ radiative decay channels. Further experimental data from BES, CLEO-c, GSI (?) will be useful for establishing these f0 states as glueball-QQ* mixing states.

  26. Thanks !

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