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## Charmonium Decays in CLEO

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**Charmonium Decays in CLEO**Tomasz Skwarnicki Syracuse University I will concentrate on the recent results. Separate talk covering Y(4260).**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**CLEO-c Data Samples • By far the largest y(3770) sample • The y(2S)sample not the largest, but still unique because of the CLEO detector capabilities (excellent tracking, EM calorimeter and PID) J/y(1S) R Ian Shipsey’s talk on Y(4260) E(e+e-) GeV 5.6pb-1, 3M y(2S) 60pb-1, scan 3.97-4.26 GeV 20.7pb-1 continuum below y(2S) 200pb-1 at 4.17 GeV 281pb-1, 1.8M y(3770)**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**cc Photon transitions: y(3770) gccJ • Rare because GE1~100-102 keV while Gy(3770)DD=25 MeV • Interesting because of well grounded potential model predictions for GE1[y(13D1) gc(13PJ)]: • Is y(3770) a regular cc state? • Effects due to 13D1 - 23S1 mixing? • Reliability of the GE1 predictions for states above the open charm threshold? • Two complementary methods: • ccJ gJ/y, J/y e+e-,m+m- • Excellent background suppression but poor sensitivity to cc0 • ccJ K+K- , K+K-p+p- , p+p-p+p- , p+p-p+p-p+p- • More backgrounds but good sensitivity to cc0 • Total energy-momentum constraints suppress the backgrounds and improve the photon energy resolution • y(2S) gccJ as control sample n 2S+1 L J y(2S) ccJ y(3770) n=2 2K,2K2p,4p,6p J/y n=1 l+l- S= 0 1 0 1 0 1 L= 0 1 2**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Photon transitions: y(3770) gccJ CLEO-CONF-06-6 hep-ex/0605070 PRL 96 182002 (06) g hadrons cc0 signal g hadrons y(2S) bkg other bkg**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Photon transitions: y(3770) gccJ In non-relativistic limit no J-dependence of the E1 matrix element Dominant J-dependence signature of the 13D1 state • y(3770) photon transition rates fit the pattern expected for the 13D1 cc state**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**23S1 – 13D1 Mixing ? Theoretical curves from the non-relativistic calculations by J. Rosner hep-ph/0411003 CLEO-c results y(2S) y(3770) • No consistent solution can be obtained in the non-relativistic approach • Mixing angle is small**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Importance of relativistic corrections • Non-relativistic calculations overestimate photon transition rates for the charmonium • Qualitatively, potential model predictions work for the 13D1 state equally well as for the 23S1 state Non-relativistic Rosner hep-ph/0411003 Ding,Qin,Chao PRD44,3562(91) Relativistic Based on CLEO-c results (J-averaged) ( GeV-1 ) Eichten,Lane,Quigg PRD69,094019(04) Barnes,Godfrey,Swanson PRD72,054026(05)**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**non-DD decays of y(3770) CLEO PRL,96,082004 (06) • No evidence for anomalously large non-DD component e+e-(2S) (J/+-) (3770) J/+- missing event energy (GeV) after finding +, -, J/(ll) CLEO PRD,73,012002 (06) (many upper limits presented in this paper too) CLEO-CONF-06-7 CLEO hep/ex-0603026 vs. CLEO PRL,95,121801 (05) CLEO PRL,96,092002 (06) vs. (9 ± 2 ± 6)% BES-II Gang Rong’s talk**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Results relevant for the interpretation of X(3872) • Combining results from the previous slides: • X(3872) cannot be 13D2 cc state! • A moot point by now, since Belle, CDF, BaBar have shown X(3872) is JPC=1++**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki** tag • Ksf (p+p-)(K+K-) D0 M(Ksf) GeV Results relevant for the interpretation of X(3872) • D0 mass: • y(3770) D0D0 • Very small background • D0, Ks, f have small momenta • D0 mass scale well calibrated via Ks, f masses • 1864.85±0.15±0.20 MeV CLEO PRELIMINARY • 1864.5±0.40 MeV PDG’06 fit • 1864.1±1.00 MeV PDG’06 average • MX(3872)-MD0D0*= MX(3872)-(2MD0+DMD0*-D0)= • +0.1±1.0 MeV PDG’06 • -0.4±0.7 MeV PDG’06+CLEO • The error is now limited by the X(3872) mass measurement • Accidental mass coincidence even less likely. D0D0* molecule, other 4-quark state with small binding energy, or a threshold cusp?**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**y(2S) as ccJ factory • e+e−→ y(2S) • 5pb-1, CLEO III+c, 3M y(2S) • by the end of the year×10 • y(2S)→cJ,J=0,1,2 • B~9% each J,“cJ factory” • observed in inclusive analysis • B(cJ→hadrons)are not well known • Selected analyses of cJ hadronic decays: • Channels involving neutrals: • cJ →η(’)η(’) • cJ → h+h−h0,3-body decays, Dalitz plot analysis CLEO PRD,70, 112002 (2004) c1 c0 c2**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**ccJh(’)h(’) B(c0) = 0.31 ± 0.05 ± 0.04 % B(c0//) = 0.18 ± 0.04 ± 0.02 % B(c0/) < 0.05% (90% CL) B(c2) < 0.05% (90% CL) B(c2 //) < 0.03% (90% CL) B(c2/) < 0.023% (90% CL) cc2 CLEO preliminary cc0 cc1 cc1 spin-parity forbidden Theoretical model by:Qiang Zhao, PRD,72,074001(05) BES E835 Fits all r = Double-OZI/Single-OZI**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**cc2 cc2 cc2 cc1 cc1 cc1 cc0 cc0 cc0 Analysis of cJ→h0h+h− • See results on the next slide cc2 cc1 cc0 hpp hpp K0Kp p0KK hKK h’pp p0pp LKp**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Analysis of cJ→h0h+h− CLEO-CONF-06-9 • Most of them are the first observations! • Statistics in c1→hp+p−, K+K−p0, K0sKp sufficient for Dalitz plot analysis of resonant substructure (following slides) (in %) CLEO PRELIMINARY (upper limits at 90% C.L.)**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Dalitz plot analysis of c1→hp+p− • May offer the best way to determine a0(980) parameters in the future • 10x increase in statistics expected this year f2(1270) CLEO PRELIMINARY a0(980) a0(980)**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Dalitz plot analysis of c1→ K+K−p0 • Analyzed together with K0sKp • see the next slide for the fit results K*(892) K*(1430) a0(980) K*(892) K*(1430)**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Dalitz plot analysis of c1→ K0sKp CLEO PRELIMINARY • K*(892)K,a0(980)p clearly seen • Need more data to sort out other contributions KKp fit results K*(892) K*(1430) Model dependent a0(980) K*(892) K*(1430)**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Search for y(2S) →hc(1S) p+p-p0 • B(y(2S) →hc p+p-p0) < 0.1% (90% C.L.) • Rules out “survival before annihilation” model by P.Artoisenet et al. PLB,628,211 (05) invented to explain the “rp puzzle” (predicted B > 1%) CLEO PRELIMINARY MC CLEO CLNS 06/1965 data hc→ K+K-p0, p+p-h, K+K-K+K-, p+p-p+p-, K0K-p+ hc**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Analysis of y(2S) → 2 pseudo-scalars CLEO hep-ex/0603020 CLEO-CONF-06-8 • Confirm BES results • The phase difference D between the EM and strong amplitudes around 90o, which is consistent with the J/y value, contrary to some theoretical speculations that it might be very different**Charmonium in CLEO ICHEP'06 Moscow Tomasz Skwarnicki**Summary • Potential models predict GE1for y(3770) gccJ equally well as for y(2S) gccJ • No evidence for anomalously high y(3770) non-DD • y(3770) appears to be standard 13D1 cc state with a small admixture of 23S1 • Preliminary precision measurement of D0 mass improves MX(3872)-MD0D0*determination to -0.4±0.7 MeV • Vast improvement in measurements of exclusive hadronic decay modes of the ccJ states. • An order of magnitude increase in y(2S) statistics (x10) expected soon. Significant improvement in y(3770) statistics (x3) expected by 2008.