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Recent  (2S) and J/  results from CLEO

Recent  (2S) and J/  results from CLEO. PANIC05, Santa Fe, NM Oct 24 - 28, 2005. GuangShun Huang Purdue University (Representing the CLEO collaboration). Ψ (2S) → XJ/ ψ J/ ψ → l + l - Ψ (2S) → baryon pair Ψ (2S) → multi-body hadrons Ψ (2S) → K S K L. Charmonium.

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Recent  (2S) and J/  results from CLEO

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  1. Recent (2S) and J/ results from CLEO PANIC05, Santa Fe, NM Oct 24 - 28, 2005 GuangShun Huang Purdue University (Representing the CLEO collaboration) • Ψ(2S) → XJ/ψ • J/ψ → l+ l- • Ψ(2S) → baryon pair • Ψ(2S) → multi-body hadrons • Ψ(2S) → KSKL PANIC05, Santa Fe, NM, Oct 24–28

  2. Charmonium PANIC05, Santa Fe, NM, Oct 24–28

  3. CLEO-c detector B=1 Tesla 0.6% p @ 1GeV/c 2.2% E @ 1 GeV 5% E @100 MeV Track 93% of 4π RICH 80% of 4π Data sets: Ψ(2S) (3686) 5.63pb-1 Cont. (3670) 20.70pb-1 PANIC05, Santa Fe, NM, Oct 24–28

  4. CLEO vs other experiments Ψ(2S) in millions of resonance decays CLEO-c Ψ(2S) data sample is not the biggest in the world, but the detector is excellent (both tracking andg detection), and we also have a large continuum data sample. PANIC05, Santa Fe, NM, Oct 24–28

  5. y(2S)→X J/y(1S) • Hadronic transitions (X=pp,h,p0): • BR(y(2S)→XJ/y(1S)) needed in phenomenological models; • BR(y(2S)→ p+p- J/y(1S)) often used as normalization; • BR(y(2S)→ p0 J/y(1S)) / BR(y(2S)→ h J/y(1S)) is sensitive to • mu-md (isospin violation) • Previous ratio of BR(y(2S)→ p0p0 J/y(1S)) / BR(y(2S)→ p+p- J/y(1S)) at odds with isospin symmetry (beyond amount of expected violation) • Photon cascades y(2S)→ gccJ(1P)→ ggJ/y(1S): • Serves as determination of BR(ccJ (1P) → gJ/y(1S)) • Inclusively measured BR(y(2S)→X J/y(1S)): • Si BR(y(2S)→Xi J/y(1S)) = BR(y(2S)→X J/y(1S))inclusive • a powerful check on validity of the measurements • Test if “12% rule” satisfied with inclusive decays PANIC05, Santa Fe, NM, Oct 24–28

  6. Inclusive BR(y(2S)→X J/y(1S)) y(2S) data • Inclusive • dilepton pairs: • Electrons and muons identified with loose E/p cuts cut cut J/y y(2S) BW tail scaled continuum y(2S) continuum subtracted cc0,2 → K+K- p+p- MC PANIC05, Santa Fe, NM, Oct 24–28

  7. Exclusive BR(y(2S)→ gccJ(1P)→ ggJ/y(1S)) • Fully reconstructed events • h→ gg,p0→ gg suppressed by 250<p(J/y)<500MeV, which corresponds to 227<m(gg)<522MeV: • Other experiments used direct cuts on m(gg) (they really didn’t have a choice) • In CLEO-c resolution of m(gg) calculated via p(J/y →l+l-) is actually better than calculated via gg cc1 cc0 cc2 PANIC05, Santa Fe, NM, Oct 24–28

  8. Ψ(2S) → XJ/ψ Results • Best measurements in all modes • Isospin symmetry restored in p0p0 /p+p- • Significantly higher BR(ccJ (1P) → gJ/y(1S)) Phys.Rev.Lett94,232002(2005) All PDG values are scaled by CLEO central values PANIC05, Santa Fe, NM, Oct 24–28

  9. B(J/l+l-) from Ψ(2S) → π+π-J/ψ • Used in determination of Gtot(J/y) and Gee(J/y) from s(e+e-→ J/y→hadrons) • Sensitive to the wave function at the origin: used to test potential models • In this analysis we use • Ψ(2S) → π+π-J/ψ and measure N(J/l+l-) & N(J/X) (determined from the inclusive π+π- recoil mass distribution). e+e- μ+μ- M(l+l-) Mrecoil Mππ π+π-J/ψ (J/ψ → l+l-) solid line: MC, points: data PANIC05, Santa Fe, NM, Oct 24–28

  10. Results for J/ψ → e+e- and μ+μ- PRD 71, 111103(R) (2005) B(J/e+e-) = (5.9450.0670.042)%, rel. 1.3%B(J/+-) = (5.9600.0650.050)%, rel. 1.4% B(J/l+l-) = (5.9530.0560.042)%B(J/e+e-)/B(J/+-) = (99.71.20.6)% PDG B(J/e+e-) = (5.930.10)%, rel. 1.7%B(J/+-) = (5.880.10)%, rel. 1.7% PANIC05, Santa Fe, NM, Oct 24–28

  11. Ψ(2S) to light hadrons The branching fraction for (2S) decaying to light hadrons can be computed as the difference between unity and the branching fraction sum of all exclusive direct transitions measured in this work (and previous CLEO results). That is: 1  (ΣB[(2S)J/+h]  ((2S)  cJ and (2S) c)  dilepton branching fractions This yields B[(2S)light hadrons] = (16.92.6)%. To be compared with that of the J/, B(J/light hadrons) = (86.80.4)%, yielding a ratio of (19.43.0)% which is ~ 2.2σ above B[(2S)l+l-]/B(J/l+l-) = (12.70.5)%. PANIC05, Santa Fe, NM, Oct 24–28

  12. Hadronic decays of the ψ(2S) • (2S): the “12% rule”? For the charmonium system (cc annihilation), decay rate  |(0)|2, • Information on resonant vs. non-resonant in multi-body final states. • Hints for S-D mixing between (2S) and (3770). • PID with combined RICH-dE/dx information; • Scale continuum data for non-resonant subtraction; • Use scaled energy and/or resonant mass to isolate signal. _ PDG04 PANIC05, Santa Fe, NM, Oct 24–28

  13. Hadronic decays of the ψ(2S) Scaled energy for baryon anti-baryon Scaled energy and resonant production in multi-particle hadronic decays PANIC05, Santa Fe, NM, Oct 24–28

  14. Results for Ψ(2S) → baryon anti-baryon 2 first observations Phys. Rev. D 72, 051108(R) (2005) NS = S(2S) - B(2S) - Bcf - f  Bc , Br=Ns/( N(2S)) S=0 -1 -2 J=3/2 To be compared with ( 12.7  0.5 )% First observation PANIC05, Santa Fe, NM, Oct 24–28

  15. Results for Ψ(2S) → multi-body 13 first observations Phys. Rev. Lett 95, 062001 (2005) 12.7  0.5 ? PANIC05, Santa Fe, NM, Oct 24–28

  16. The 12% rule: Qh= B((2S)h)/B(J/h)12% Qh(%) Qh(%) Reasonable agreement with the rule, in contrast to VP modes and +-0. PANIC05, Santa Fe, NM, Oct 24–28

  17. Measurement of B (Ψ(2S) → KSKL) • Reconstruct KS→π+πˉ • DO NOT reconstruct KL • Allow possible KL signature • Veto π0; veto  outsideKL cone • Scaled energy of KS: • Xbeam= EKs / Ebeam • 0.98 < Xbeam <1.02 B(Ψ’→ KS KL) = (5.84 ± 0.80 ± 0.43)×10-5!!!CLEO PRELIMINARY!!! B(Ψ’→ KS KL) = (5.24 ± 0.47 ± 0.48)×10-5BES[PRL.92:052001,2004] PANIC05, Santa Fe, NM, Oct 24–28

  18. Summary • CLEO-c has made a variety of measurements of charmonium transitions: Ψ(2S) → XJ/ψ, J/ψ→l+ l-, Ψ(2S)→baryon pair, Ψ(2S)→multi-body hadrons and Ψ(2S) → KSKL. • The results presented are part of a continuing detailed systematic analysis of charmonium decays by the CLEO collaboration. Most of the results are either first observations or of higher precision than previous measurements. • CLEO-c plans to continue running for the next few years in the charm region both for the bound states and for open charm meson production. PANIC05, Santa Fe, NM, Oct 24–28

  19. Backup slides PANIC05, Santa Fe, NM, Oct 24–28

  20. Exclusive BR(y(2S)→pp J/y(1S)) • Fully reconstructed events: • Energy-momentum conservation • Dilepton mass and dipion-recoil mass consistent with J/y h→ p0p0p0 h→ p+p-p0 PANIC05, Santa Fe, NM, Oct 24–28

  21. Exclusive BR(y(2S)→h,p0 J/y(1S)) • Fully reconstructed events • h→ gg and p+p-p0 • p0→ gg h→ gg + p+p-p0 PANIC05, Santa Fe, NM, Oct 24–28

  22. N+- J/, J/X: Fitting Recoil Mass Spectrum • +-(J/X): • pT>150 MeV/c, |cos|<0.83, m(+-)=400-600 MeV • Fit M(+--recoil) for NX • M(+--recoil) uses only the pions, hence ~independent of what the J/ does. • Efficiency is obtained by weighting a set of basis modes to produce J/X mix. PANIC05, Santa Fe, NM, Oct 24–28

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