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Charmonium Results from CLEO

Charmonium Results from CLEO. Y. Kubota representing the CLEO collaboration 18 Aug 2004. Outline. Motivation  (2S)  cJ branching fractions  c ( ’ ) masses and  (2S)  c branching fractions X (3872) search ( preliminary ). Motivation. Better understanding of QCD

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Charmonium Results from CLEO

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  1. Charmonium Results from CLEO Y. Kubota representing the CLEO collaboration 18 Aug 2004

  2. Outline • Motivation • (2S)cJ branching fractions • c(’) masses and (2S)c branching fractions • X(3872) search (preliminary) CLEOc Charmoium results

  3. Motivation • Better understanding of QCD • Needed for better measurements of electroweak processes • Good testing ground of LQCD • Good practice to understand future physics, which involves strong coupling (Lepage) • Heavy quarkonia • relativistic effects are smaller CLEOc Charmoium results

  4. cJ • cJ: • well established. • E1 transitions from (2S) (transition rates) •  fusion production (Γγγ’s) • pp annihilation (masses, widths) CLEOc Charmoium results

  5. c(’) • c: • well established. • M1 transition from J/ & (2S) (mass, transition rates) •  fusion production (mass, width, Γγγ’s) • pp annihilation (mass, width) • c’: • Established two years ago by Belle (B decays, etc.), and CLEO and Babar ( fusion production) • Crystal Ball result using M1 transition from (2S) is most likely false. CLEOc Charmoium results

  6. Photon Spectrum (2.7 pb-1) • No 0 suppression • cos >0.5 – used in analysis • Max 0 suppression CLEOc Charmoium results

  7. cFit results MIP Solid: Signal+background Dotted: generic background only Dashed: generic + MIP background Background subtracted Systematic errors: Event selection, Fitting, 0 suppression J/c 10000 0 CLEOc Charmoium results

  8. (2S)cJBranching Fractions • CLEOc & C-Ball agree well. • Ratios of BF’s very close to 1 • within 3-8% systematic errors • NRQCD expectations ~ (2J+1)Eγ3 • Relativistic effects important? CLEOc Charmoium results

  9. cFit results Solid: Signal+backgroundDotted: generic background onlyBackground subtracted CLEOc Charmoium results

  10. c mass and (2S)c BF • mc = (2970±7) MeV • Consistent w/ world average of ~2980 MeV. • B((2S)c) = (0.32±0.04±0.06)% • Sensitive to relativistic corrections. • Crystal Ball obtained (0.28±0.06)% for Γc = (11.5±4.5)MeV. • CLEOc would have given (0.25±0.06)% for this Γc – entirely consistent. • About expected level by theories. CLEOc Charmoium results

  11. (2S)c(2S) • No trace of this transition at Eγ = 91 MeV • BF < 0.2% at 90% C.L. • C-Ball presented BF ~ (0.2-1.3)% with 95% C.L. • Given the mass & width of c(2S) of 3638 and 25 MeV at recent experiments (Belle, CLEO, Babar), we expect Eγ = 47 MeV and width ~ 10 MeV • No meaningful sensitivity exists at this energy and width. CLEOc Charmoium results

  12. X(3872): background • Found by Belle in B decays • Confirmed by CDF and D0 – general hadronization • Mass = 3872 MeV • Width – smaller than resolution ~ 2 MeV • Decays to π+π–J/ψ; no report on π0π0J/ψ • Has not been found in γχ, γJ/ψ, DD, D0D0π0 CLEOc Charmoium results

  13. What is X(3872)? • Charmonium? • From narrow width, • 13D2(2– –), 13D3(3– –), 21P1(1+–) all C = –, or • 11D2(2–+), 23P1(1++) all C = + • DD* molecule? • Close to DD* threshold and from lack of π0π0J/ψ decays • ρ0J/ψ decay? • Then X(3872) will most likely be 0–+ or 1++. • Glueball? • Three-gluon glueball of 1– – at m = 3850 MeV predicted. CLEOc Charmoium results

  14. JPC determination • It will be useful to know what JPC of X(3872) is. • BES showed that its production in ISR (e+e–γe+e–γX(3872) is invisible (ECM = 4 GeV) • Γee×B(π+π–J/ψ) < 10 eV (90% C.L.) • JPC1– –? • CLEO seeks X(3872) in 15 fb-1 of data using • γγ fusion (C = + & J = evenonly) • ISR (ECM = 10 GeV) CLEOc Charmoium results

  15. Event characteristics • Missing momentum/energy in the beam directions • In γγ fusion, missing momentum ~ 0 • In ISR, missing momentum ~ missing energy • Missing momentum perpendicular to the beam is small • 4 charged particles • No neutral energy CLEOc Charmoium results

  16. Result • Clear peak for ψ(2S) • No event for X(3872) CLEOc Charmoium results

  17. Distinguishing γγ fusion from ISR • Due to the difference in the beam-direction motion of X(3872) candidates, we can distinguish the two production mechanism. ISR γγ fusion CLEOc Charmoium results

  18. Final results • (2J+1)Γγγ×B(Xπ+π–J/ψ) < 12.9 eV (90% C.L.) • Γee×B(π+π–J/ψ) < 8.0 eV (90% C.L.) CLEOc Charmoium results

  19. Interpreting results • (2J+1)Γγγ×B(Xπ+π–J/ψ) < 12.9 eV • Assume B(BKX) ~ B(BKψ(2S))  • B(Xπ+π–J/ψ) = 2%  • (2J+1)Γγγ < 0.6 keV • Compare it to (2J+1)Γγγ for ηc, χc0, and χc2. • 7.4 keV (ηc); 2.6 keV (χc0); 2.6 keV (χc2) • Γee×B(Xπ+π–J/ψ) < 8.0 eV (90% C.L.) • This is less than 1% of ψ(2S) production in ISR events. CLEOc Charmoium results

  20. Summary • Precise measurements of rates for • (2S)cJ and • (2S)c • Limit on (2S)c(2S) • Upper limits on X(3872) productions in • ISR • γγ fusion CLEOc Charmoium results

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