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Charmonium above (3770)

Charmonium above (3770). Study of resonance formation in energy regime above y (3770). CLEO probes direct production of “new states” via coupling to electron-positron collisions Constrains possible quantum numbers (as does production in ISR a la’ Belle/BaBar)

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Charmonium above (3770)

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  1. Charmonium above (3770) • Study of resonance formation in energy regime above y(3770). • CLEO probes direct production of “new states” via coupling to electron-positron collisions • Constrains possible quantum numbers (as does production in ISR a la’ Belle/BaBar) • Take advantage of recent ‘scan’ to locate peak of Ds production cross-section in region between 3.9-4.3 GeV c.o.m. and study new charmonia. • THANKS TO BRIAN HELTSLEY & HANNA MAHLKE-KRUGER, FROM WHOM I SHAMELESSLY LIFTED SLIDES WHOLESALE!

  2. Charmonium, retrospective • J/y(3097) observation (1974) ushers in modern heavy-quark era • Spectroscopy of states below threshold generally conforms to potential model expectations • Belle ushers in “new” era looking at mass recoiling against strange-meson states in exclusive B-decays X(3872), etc… • Recent charmonium Renaissance; • CLEO-c well poised to contribute!

  3. (some) recent CLEO-c charmonium papers… • Measurement of Gee(J/y), Gtot(J/y), Gee[y(2S)]/Gee(J/y)hep-ex/0512046 • Two Photon Width of chic2 (submitted to PRL) • Observation of the 1P1 State of Charmonium Phys. Rev. Lett.95:102003,2005 • Measurement of Branching Fractions for J/yl+ l- Phys. Rev. D71:111103,2005 • Branching Fractions for psi(2S) to J/psi Transitions Phys. Rev. Lett.94:232002,2005

  4. Comment on J/y(3770)DDbar CLEO has now determined (3770)DD/(3770)hadrons ECM=3671 MeV evt yield (x1000) ECM=3770 MeV evt yield (x1000) D(hadronic-DD)=(0.01+/-0.08+/-0.4) nb Open charm production nearly saturates (3770)!

  5. y(3770), cont. • “Almost” saturates – CLEO has published: • Dipion transitions to (1S) state, submitted PRL • Radiative transitions to cc,1 state, submitted PRL • But not hadronic charmless modes (30 modes in two analyses) Phys.Rev. D73 (2006) 012002

  6. Pre-CLEO cross-section tabulation (PDG)

  7. Eric Swanson, hep-ph/0601110

  8. How do dipion transitions compete with allowed DD decays?

  9. CLEO study of charmonia > (3770) • Search in dipion (or even dikaon transitions): • X(J/y)pp; for both neutral and charged dipions. • J/y decays leptonically, resulting in very clean & distinctive final state. • Complications: • Tails of Breit-Wigner resonances lurk everywhere • E.g., some of observed (J/y)pp final state at high energies may be either tail of y(2S) or ISR radiation to peak of y(2S). Former calculable, latter distinctive by missing energy / momentum-imbalance carried by missing ISR photon (typically down beampipe). • Advantage: Opportunity to calibrate systematics…

  10. Expectation Note: ISR photon not reconstructed; distinguishable on basis of missing momentum

  11. Y(4260) reconstruction • Data taken directly on peak (13.2/pb), part of a scan of 3.974.26 GeV center-of-mass range. • Note: not enough data to measure intrinsic width of putative resonance (88+/-23+/-5 MeV, BaBar) or mass (4259+/-8 MeV, BaBar) • Tabulate contributions to (J/y)pp; J/yl+l- final state, look for excess beyond contribution expected from (2S) + non-resonant processes • Cut on missing momentum to exclude ISR (2S) contributions

  12. (y(2S) ISR off-scale)

  13. Compile observed cross-section as function of c.o.m. energy

  14. Dipion mass distributions look “Yan-like”

  15. Search for 3 states in other modes • Extend search to include many other modes, including hadronic transitions to (2S), radiative and hadronic transitions to cc states, dipion transitions to phi, and other hadronic transitions to J/y • No signals found in any other modes; upper limits set on (BR*cross-section)

  16. So….

  17. 1. hep-lat/0512029 [abs, ps, pdf, other] : • Title: Y(4260) on the latticeTWQCD Collaboration: Ting-Wai Chiu, Tung-Han Hsieh • 2. hep-ph/0511107 [abs, ps, pdf, other] : • Title: The Y(4260) as an omega chi_{c1} molecular stateC.Z. Yuan, P. Wang, X.H. Mo • 3. hep-ph/0510228 [abs, ps, pdf, other] : • Title: One Explanation for the Exotic State Y(4260)Cong-Feng Qiao (GUCAS) • 4. hep-ph/0507177 [abs, ps, pdf, other] : • Title: Possible Molecular Structure of the Newly Observed Y(4260) Authors: Xiang Liu, Xiao-Qiang Zeng, Xue-Qian Li • 5. hep-ph/0507119 [abs, ps, pdf, other] : • Title: Suppressed decay into open charm for the Y(4260) being an hybrid Authors: E. Kou, O. Pene • 6. hep-ph/0507062 [abs, ps, pdf, other] : • Title: Four Quark Interpretation of Y(4260)Authors: L. Maiani, F. Piccinini, A.D. Polosa, V. Riquer • 7. hep-ph/0507025 [abs, ps, pdf, other] : • Title: The Possible Interpretations of Y(4260)Authors: Shi-Lin Zhu Recent theoretical interest

  18. And…. • 1. hep-ph/0511005 [abs, ps, pdf, other] : • Title: Quark--antiquark states and their radiative transitions in terms of the spectral integral equation. II. CharmoniaV. Anisovich, L.Dakhno, M.Matveev, V.Nikonov, A.Sarantsev • 2. hep-ph/0411291 [abs, ps, pdf, other] : • Title: Leptonic widths of high excitations in heavy quarkoniaAuthors: A.M. Badalian, A.I. Veselov, B.L.G. Bakker • 3. hep-ph/0410361 [abs, ps, pdf, other] : • Title: Charmed quark component of the photon wave functionAuthors: V.V. Anisovich, L.G. Dakhno, V.N. Markov, V.A. Nikonov, A.V. Sarantsev • 4. hep-ph/9507407 [abs, ps, pdf, other] : • Title: Do psi(4040), psi(4160) signal Hybrid Charmonium?Authors: Frank E. Close, Philip R. Page

  19. Summary • Confirm BaBar e+e-Y(4260)p+p-J/y: • s=52+/-12+/-4 pb • New observations of e+e-Y(4260)p0p0J/y and e+e-Y(4260)K+K-J/y (s=23+12-8 pb and 9+9-5 pb) • Similar dipion transitions from (4040) or (4160) states not observed. • Early results favor hybrid charmonium interpretation. • CLEO intends now to exhaustively study particle production in this energy regime!

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