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Study of Charmonium Resonance Formation Above Y(3770) Using CLEO Data

This research investigates the formation of charmonium resonances in the energy regime above Y(3770) using data from CLEO. The study focuses on the direct production of new states through electron-positron collisions. By analyzing the recent energy scan in the region between 3.9-4.3 GeV, we explore the peak of Ds production cross-section and study its implications for charmonia, including resonance searches in various decay modes. Our findings contribute to understanding the spectrum of charmonium and the nature of these newly observed states.

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Study of Charmonium Resonance Formation Above Y(3770) Using CLEO Data

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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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