Charmonium above 3770 Study of resonance formation in

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/Ba. Bar) • Take advantage of recent ‘scan’ to locate peak of Ds production cross-section in region between 3. 9 -4. 3 Ge. V c. o. m. and study new charmonia. • THANKS TO BRIAN HELTSLEY & HANNA MAHLKE-KRUGER, FROM WHOM I SHAMELESSLY LIFTED SLIDES WHOLESALE!

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!

(some) recent CLEO-c charmonium papers… • Measurement of Gee(J/y), Gtot(J/y), Gee[y(2 S)]/Gee(J/y) hep-ex/0512046 • Two Photon Width of chic 2 (submitted to PRL) • Observation of the 1 P 1 State of Charmonium Phys. Rev. Lett. 95: 102003, 2005 • Measurement of Branching Fractions for J/y l+ l. Phys. Rev. D 71: 111103, 2005 • Branching Fractions for psi(2 S) to J/psi Transitions Phys. Rev. Lett. 94: 232002, 2005

Comment on J/y(3770) DDbar CLEO has now determined (3770) DD/(3770) hadrons ECM=3671 Me. V evt yield (x 1000) ECM=3770 Me. V evt yield (x 1000) D(hadronic-DD)=(0. 01+/-0. 08+/-0. 4) nb Open charm production nearly saturates (3770)!

y(3770), cont. • “Almost” saturates – CLEO has published: – Dipion transitions to (1 S) state, submitted PRL – Radiative transitions to cc, 1 state, submitted PRL – But not hadronic charmless modes (30 modes in two analyses) Phys. Rev. D 73 (2006) 012002

Pre-CLEO cross-section tabulation (PDG)

Eric Swanson, hep-ph/0601110

How do dipion transitions compete with allowed DD decays?

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(2 S) or ISR radiation to peak of y(2 S). Former calculable, latter distinctive by missing energy / momentum-imbalance carried by missing ISR photon (typically down beampipe). – Advantage: Opportunity to calibrate systematics…

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

Y(4260) reconstruction • Data taken directly on peak (13. 2/pb), part of a scan of 3. 97 4. 26 Ge. V center-of-mass range. • Note: not enough data to measure intrinsic width of putative resonance (88+/-23+/-5 Me. V, Ba. Bar) or mass (4259+/-8 Me. V, Ba. Bar) • Tabulate contributions to (J/y)pp; J/y l+l- final state, look for excess beyond contribution expected from (2 S) + non-resonant processes • Cut on missing momentum to exclude ISR (2 S) contributions

(y(2 S) ISR off-scale)

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

Dipion mass distributions look “Yan-like”

Search for 3 states in other modes • Extend search to include many other modes, including hadronic transitions to (2 S), 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)

1. hep-lat/0512029 [abs, pdf, other] : Recent theoretical interest Title: Y(4260) on the lattice TWQCD Collaboration: Ting-Wai Chiu, Tung-Han Hsieh 2. hep-ph/0511107 [abs, pdf, other] : Title: The Y(4260) as an omega chi_{c 1} molecular state C. Z. Yuan, P. Wang, X. H. Mo 3. hep-ph/0510228 [abs, pdf, other] : Title: One Explanation for the Exotic State Y(4260) Cong-Feng Qiao (GUCAS) 4. hep-ph/0507177 [abs, 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, 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, pdf, other] : Title: Four Quark Interpretation of Y(4260) Authors: L. Maiani, F. Piccinini, A. D. Polosa, V. Riquer 7. hep-ph/0507025 [abs, pdf, other] : Title: The Possible Interpretations of Y(4260) Authors: Shi-Lin Zhu

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

Summary • Confirm Ba. Bar e+e- Y(4260) p+p-J/y: – s=52+/-12+/-4 pb • New observations of e+e- Y(4260) p 0 p 0 J/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!