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Экзотические и стандартные векторные состояния чармония

-. с. с. Галина Пахлова ИТЭФ , коллаборация Belle. Экзотические и стандартные векторные состояния чармония. c. c. Above open charm threshold five conventional states are measured broad states are expected. Conventional Charmonium in Quark Model. n (2S+1) L J

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Экзотические и стандартные векторные состояния чармония

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  1. - с с Галина Пахлова ИТЭФ, коллаборация Belle Экзотические и стандартные векторные состояния чармония

  2. c c • Above open charm threshold • five conventional states are measured • broad states are expected Conventional Charmonium in Quark Model n(2S+1)LJ n radial quantum number S total spin of q-antiquark L relative orbital ang. mom. L = 0, 1, 2 ...correspond to S, P, D J = S + L P = (–1)L+1parity C = (–1)L+Scharge conj. • Below open charmthreshold • all expected charmonium statesare observed • most are narrow Галина Пахлова

  3. Exotic charmoniumlike states Multiquark states Molecular state two loosely bound charm mesons quark/color exchange at short distances pion exchange at large distance Tetraquark tightly bound four-quark state Charmonium hybrids States with excited gluonic degrees of freedom Hadro-charmonium Specific charmonium state “coated” by excited light-hadron matter Threshold effects Virtual states at thresholds Charmonium states with masses shifted by nearby D(*)D(*) thresholds March 1976 c November 1976 u Search for exotics: states with ... • JPC forbidden for charmonium • Extremely narrow width • Non-zero charge [cucd], strangeness [cdcs] or both [cucs] • Obvious sign of multiquark states c g – – – – c c c c ─ π ─ ─ c π – – u u c π u Exotics more easier to identify among cc and bb states ─ ─ Галина Пахлова

  4. Y(3940) Z(4430)+ X(3872) Y(3915) Z(3930) Z+1 Z+2 X(4160) Y(4260) X(3940) Y(4008) X(4360) Y(4660) Y(4350) Y(4350) Y(4140) Галина Пахлова

  5. B-factories e+e–→(4S) and nearby continuum: Ecms ~ 10.6GeV L ~ 2.1x1034/cm2/s at Belle 950 + 530 fb–1in total Belle + BaBar Charmonium from B-meson decays, initial state radiation (ISR) , double cc production, continuum productionand γγ fusion Tevatron D0 CDF pp collider E ~ 1.8 TeV L~ 4fb–1 per experiment ─ Belle Charm factories CLEO-cBES-II e+e–→J/, (2S), (3770) scan 3.8-4.8 GeV L~1032/cm2/s BaBar Галина Пахлова

  6. Charmoniumlike 1– –family Галина Пахлова

  7. c e+ e+ e+ γ Use ISR to measure open&hidden charm exclusive final states s =(Ecm– Eγ)2 – p2 e– e– e– c ISR at B factories • Quantum numbers of final states are fixed JPC = 1– – • Continuous ISR spectrum: • access to the whole √s interval • αemsuppression compensated by huge luminosity • comparable sensitivity to energy scan (CLEO-c, BES) Галина Пахлова

  8. e+e–→J/ψπ+π–γISR Y(4260)... Y(4008)? arXiv:0808.1543 NEW Y(4260) 344±39 ev Y(4008) 454 fb-1 Br(J/ψπ+π–)Γee , eV Solution1 Y(4008)Solution2 < 0.7 90% CL Solution1 Y(4260)Solution2 7.5±0.9±0.8 Absence of open charm production is inconsistent with conventional charmonium Галина Пахлова

  9. e+e–→ψ(2S) π+π–γISR Y(4360), Y(4660) ... PRL 98, 212001 (2007) PRD 78, 014032 (2008) Y(4360)→ψ(2S)ππ Y(4660)? PRL 99, 142002 (2007) Y(4360) Y(4660) 6.1σ 298 fb-1 Y(4660) 5.8σ Y(4360) 8σ 670 fb-1 2-BW fit with interference Solution1Solution2 Br(ψ(2S)π+π–)Γee , eV Y(4360) Y(4660) Combined fit to BaBar&Belle data on e+e–→(2S) π+π–γISR Best measurements of Y(4360) and Y(4660) Assume all the cross sections are due to Y(4360) and Y(4660) added coherently Absence of open charm production is inconsistent with conventional charmonium Галина Пахлова

  10. R(s) = σ(e+e–→hadrons)/σ(e+e–→μ+μ–) – Ruds (4415) (4415) (4040) (4040) (3770) (3770) ψ(4160) ψ y ψ y (4160) ψ y 4360) 4325) 4008) 4008) y Y( Y( Y( Y( 4260) 4260) (4660) (4660) Y( Y( Y Y if R if R =2.285 =2.285 ± ± 0.03 0.03 Durham Data Base Durham Data Base uds uds Y states vs inclusive cross section e+e–→hadrons • Peak positions forM(J/) & M((2S))significantly different • Y(4260)mass corresponds to dip in inclusive cross section Галина Пахлова

  11. 4660 4350 4260 4008 Potential models & Y states No room for Y states among conventional 1– – charmonium S.Godfrey and N.Isgur PRD32,189 (1985) 33S1 = (4040) 23D1 =(4160) 43S1=(4415) masses of predicted 33D1 (4520) 53S1 (4760) 43D1(4810) are higher (lower) Галина Пахлова

  12. Interpretations of Y states Y(4360) &Y(4660) are conventional charmonia with shifted masses Y(4360) = 33D1 , Y(4660) = 53S1 G.J Ding, J.J.Zhu, M.L.Yan, Phys.Rev.D77,014033 (2008) A.M.Badalyan, B.L.G.Bakker, I.V.Danilkin, Phys.Atom.Nucl.72,638,(2009) 43S1 ≠ ψ(4415) =43D1(4661); Y(4360)=43S1(4389) , Y(4660)=53S1 (4614)or43D1(4661) J.Segovia, A.M.Yasser, D.R.Entem, F.Fernandez Phys.Rev.D78,114033,(2008). Charmonium hybrids Zhu S.L.; Close F.E.; Kou E. and Pene O. The lightest hybrid is expected by LQCD around 4.2 GeV The dominant decays Y(4260)→D(*)D(*)π, via virtual D** Hadro-charmonium Specific charmonium state “coated” by excited light-hadron matter S.Dubinskiy, M.B.Voloshin, A.Gorsky Multiquark states [cq][cq] tetraquark Maiani L., Riquer V., Piccinini F., Polosa A.D. DD1 or D*D0 molecules Swanson E.; Rosner J.L., Close F.E. Heavy meson hadronic molecules Y(4660) is ψ(2S)f0(980) bound state F.K.Gou,C.Hanhart, S.Krewald,U.G.Meissner S-wave charm meson thresholdsLui X. Галина Пахлова

  13. Parameters of the JPC = 1– – conventional charmonia ψ(3770), ψ(4040), ψ(4160), ψ(4415) M,Γtot, Γeeremain quite uncertain and model dependent To fix the resonance parameters we need to know their decay channels to take into account their interference: • non-resonant contribution • many open charm thresholds Inclusive cross section e+e– → hadrons Галина Пахлова

  14. Phys.Lett.B660,315(2008) Rres=RBW+Rint Interference term Resonance shapes BES fit to the inclusive R spectrum All possible two-bodydecays ofψ(3770),ψ(4040), ψ(4160), ψ(4415)are included Significant effect of interference : model dependent! To reduce model dependence we need to measure exclusive cross sections to open charm final states Галина Пахлова

  15. Width, GeV ? ? ? E.Swanson, Phys.Reports 429(2006) Potential models & ψ states • Mass spectrum • In general agreement with data • Open charm decays • via nonperturbative gluodynamics • difficult to compute • good probes of strong QCD • Only inclusive measurements More theoretical and experimental efforts are required Галина Пахлова

  16. γ not reconstructed if undetectable e+ e+ D reconstructed e– – D e+e–→DD via ISR with full reconstruction • Full reconstruction of hadronic part • ISR photon detection is not required • but used if it is in the detector acceptance • Translate measured DD mass spectrum to cross section Галина Пахлова

  17. σ(e+e− →DD) Phys.Rev.D77,011103(2008) Phys.Rev. D76, 111105(2007) Phys.Rev. D80, 072001(2009) • Broad structure around 3.9 GeV • in qualitative agreement with coupled-channel model? • Some structure at 4.0-4.2 GeV • Statistics are small …ψ(4040)? ψ(4160)? • Hint of ψ(4415) σ(ee D0D0)/σ (eeD+D−) at MDD≈M(3770) Belle: 1.390.310.12BaBar: 1.78±0.33±0.24 CLEO07 1.258±0.016±0.014 BES06 1.27 ±0.12±0.08  PDG08 1.260 ± 0.021 Галина Пахлова

  18. Anomalous line-shape of σ(e+e–→hadrons) around 3.77 GeV (3770) is assumed to be a mixture of 3D1 – 23S1 cc eigenstates • inconsistent with one (3770) • blue line • Fit by two P-wave BW • with complete interference 7.6 σ • green line • without interference 7σ • yellow line • interference with G(3900) structure • seen in σ(e+e–→DD) by BaBar&Belle • red line arXiv:0807.0494 ─ Two states or DD production dynamics? observed cross section - fit with one (3770) error of the observed cross section ─ BES: B((3770)→non-DD )=(14.5±1.7±5.8)% Sum of measured non-DD < 2% Theory non-DD < 5% Re-analysis of BES 2003 data between 3.65 and 3.872 GeV Галина Пахлова

  19. H.B.Li, X.S.Qin, M.Z.Yang; arXiv 0910.4278[hep-ph] New study of ψ(3770) →DDin e+e− →DD M ψ(3770) 3776  ± 1MeV PDG08 fit 3772.92 ± 0.35MeV Γψ(3770) 28.5 ± 2.2 MeV PDG08 fit 27.3 ± 1.0 MeV • Fit to BES, Belle, BaBar e+e− →DD cross section data from 3.74 to 4.4 GeV • Include contributions of ψ(3770), ψ(4040), ψ(4160), G(3900) and continuum taking into account their interference; • Breit-Wigners forψstates and Gaussian for G(3900) • the continuum is explained as tail of ψ(2S) with M= 3686.09 MeV • Parameters of ψ(4040), ψ(4160), ψ(2S) are fixed from PDG , parameters of ψ(3770) and G(3900) are set free M G(3900) 3900  ± 20MeV ΓG(3900) 52 ± 23 MeV May solve non-DD problem, more date is needed, detailed scan at BESIII to be done Factor of 4 less than Swanson’s predictions Галина Пахлова

  20. e– γ e– reconstructed D(*)+ e+ π– D*– D0 not reconstructed but constrained e+e–→D(*)+D*– via ISR with partial reconstruction D+D*–&D*+D*– • D*– partial reconstruction • increase eff~ 10-20times • Detection of ISR photon • Translate measured mass recoil against γISR ≡ D(*)+D*–mass spectrum to cross section Галина Пахлова

  21. Exclusive e+e–→D(*)D*cross-sections Phys. Rev. Lett. 98, 092001 (2007) Phys.Rev. D80, 072001(2009) D*+D*- ψ(4415) ψ(4040) ψ(4160) ψ(4040) ψ(4160) D+D*- Y(4260) 550fb–1 ψ(4160) ψ(4040) Only statistical errors Systematic errors are similar • D*D* • complicated shape of cross section • clear dip at M(D*D*) ~ 4.26GeV (similar to inclusive R) • DD* • broad peak at threshold (shifted relative to 4040 GeV) Галина Пахлова

  22. BaBar: e+e−→D(*)D* Phys.Rev. D79, 092001(2009) DD DD* D*D* 384 fb-1 • Full reconstruction of hadronic part • Both charged and neutral final states • Fit by sum of ψ states with • fixed masses&widths from PDG (due to limited statistics) No evidence is found for Y(4260)→ DD, DD*,D*D* Br ratios seem to disagree with potential models … … uncertainties are too large Галина Пахлова

  23. Belle vs BaBar: σ(e+e−→D(*)D*) Phys. Rev. Lett. 98, 092001 (2007) New Phys.Rev. D79, 092001(2009) Sum of two body open charm final states Belle & BaBar results are in very good agreement Галина Пахлова

  24. γ not reconstructed if undetectable e+ e+ D(*) e– D reconstructed π Three-body final states D0 D(*)− π+ • Full reconstruction of hadronic part • ISR photon detection is not required • but used if it is in the detector acceptance • Translate measured DD(*)π mass spectrum to cross section Галина Пахлова

  25. Phys.Rev.Lett.100,062001(2008) Consistent with ISR production 670 fb-1 e+e− D0D–+ at s ~ 4−5 GeV via ISR Clear ψ(4415) →DDπ signal Галина Пахлова

  26. Phys.Rev.Lett.100,062001(2008) DD*2(2460) 670 fb-1 ~10σ M = 4411 ± 7 MeV Γtot = 77 ± 20 MeV Nev= 109 ± 25 DDπ non DD*2(2460) Consistent with BES, Phys.Lett.B660,315(2008) PDG06, Barnes at.al Phys. Rev. D72, 054026 (2005) Resonant structure in (4415)D0D–+ • M(D0π+) vs M(D–π+) from ψ(4415) region • Clear D*2(2460) signals • No non-D*2(2460) contribution Br((4415)  D(D)non D2(2460))/Br((4415) DD*2(2460))<0.22 σ(e+e–→ψ(4415))×Br(ψ(4415)→DD*2(2460))×Br(D*2(2460) →Dπ) = (0.74 ± 0.17 ± 0.07)nb Галина Пахлова

  27. γ e+ e+ reconstructed e– Λc– X X not reconstructed p Λc+ – The first charm baryons final state Partial reconstruction with anti-proton tag • Reconstruct Λc+ • Useantiproton tagfrom inclusive Λc–→p–X Br(Λc+→pX) = (50±16)% • combinatorial background suppressed by ≈ 10 • Detect the high energy ISR photon • Translate measured mass recoil against γISR ≡ Λc+ Λc– mass spectrum to cross section Галина Пахлова

  28. partial reconstruction with p tag Phys.Rev.Lett.101,172001(2008) e+e–→Λc+Λc–γISR ─ e+e–→Λc+Λc–γISR no Σ– X(4630) 8.2σ Λc(2765) Λc(2880) Λc 670 fb-1 Λc(2625) Λc(2595) Λc sidebands Mrecoil(Λc+γISR) • Clear peak in Mrec(Λc+γISR ) distribution at Λc mass At mass > 2.5 GeV/c2 • contributions from Λc+Λc–π0 • could proceed via Λc+Σ– ;violates isospin and should be strongly suppressed • andΛc+Λc–ππ • could proceed via Λc+Λc(2595)–, Λc+Λc(2625)–, Λc+Λc(2765)–, Λc+Λc(2880)– • Total refection contributions < 5% (included in systematics) • Look at Mrecoil(γISR) ≡ Mass spectra of Λc+Λc– Галина Пахлова

  29. Interpretations for X(4630) Phys.Rev.Lett.101,172001(2008) e+e–→Λc+Λc–γISR • no peak-like structure • X(4630) ≡ Y(4660)?JPC=1– – • dibaryon threshold effect? • like in B→pΛπ, J/ψ→γpp • X(4630) = Y(4660) = charmonium state53S1 or43D1 • J.Segovia, A.M.Yasser, D.R.Entem, F.Fernandez • Charmonium state63S1B.Q.Li and K.T.Chao • Threshold effect E.Beveren, G.Rupp • Y(4660) =ψ(2S)f0(980) bound state • F.K.Gou,C.Hanhart, S.Krewald,U.G.Meissner • Point-like baryons R.B.Baldini, S.Pacetti, A.Zallo • X(4630) = Y(4660)D.V.Bugg • X(4630) = Y(4660) =tetraquark D.Ebert, R.N.Fausov, V.O. Galkin Галина Пахлова

  30. Searching for hybridsvia their favorite decay modes Галина Пахлова

  31. Combinatorial bgs are estimated from sidebands DandD* Other bgs are small and taken into account Small efficiency at threshould Full reconstruction No extra tracks Detection of γISRis not required if γISR is detected M(D0D*–+γISR) is required ~ Ecm γISRis not detected γISRis detected arXiv:0908.0231 670 fb-1 Consistent with ISR production e+e− D0D*–+at s ~ 4−5 GeV via ISR Галина Пахлова

  32. 2420 2460 D*–π+ D0 π+ • in e+e– → D0 D*–π+ γisr • D1(2420)0→D*– π+←D2(2460) • D0 D*–π+ from D0D1(2420)0 &D0D2(2460)0 • e+e– →ψ(4415) →D0D2(2460)0 →D0 D–π+ is measured • Main problemis to separateD0D1(2420)0fromD0D2(2460)0 • D1(2420)0 : Γtot=20.4 ± 1.7 MeV • D2(2460)0 : Γtot=43 ± 4 MeV(PDG08) • BothDD1 & D*D2are seen ... • but the statistics is not enough to study their mass spectra! DD*π & DD1 &D*D2 Галина Пахлова

  33. New arXiv:0908.0231 Upper Limit Y(4260) ψ(4415) ψ(4415) UL at 90% CL Exclusive e+e− D0D*–+cross-section • No evident structures: only UL’s ! • Baseline fit: • RBW for (4415)&threshold function for non-resonantcontribution without interference between amplitudes • To obtain limits on XD0D*–+, X=Y(4260), Y(4360), Y(4660), X(4630) perform four fits each with one of the X states, (4415) and non-resonant contribution • Fix masses and total widths from PDG Interference could increase these UL’s by factors of 2−4 depending on the final state (for destructive solutions) σ(e+e–→ψ(4415))×Br(ψ(4415)→D0D*–π+)< 0.76 nb at 90% CL Br(ψ(4415)→ D0D*–π+) < 10.6 % at 90% CL Галина Пахлова

  34. DDπ Λc+Λc– D*D* DD*π DD* DD Contribution to the inclusive cross section Галина Пахлова

  35. σ(e+e–→open charm) via ISR D*D* Y(4260) Y(4008) ψ(4040) PRL98, 092001 (2007) ψ(4160) Y(4360) DD* PRD77,011103(2008) DD ? DDπ PRL100,062001(2008) ψ(4415) coupled channel effect? or something else? arXiv:0908.0231 DD*π PRL101,172001(2008) Y(4660) Λc+Λc– E.Eichten, et al Phys.Rev D21, 203,(1980) Y states vs exclusive cross sections • Y(4008) mass coincides with DD* peak • Y(4260)mass corresponds to dip inD*D* cross section • Around Y(4360)mass all measured cross sections are smooth • Y(4660) mass is close to Λc+Λc–peak • Signigicant “peak-like” enhancement near 3.9 GeV in ee→DD 30 years ago! Галина Пахлова

  36. DD DD* D*D* DDπ DD*π Λ+c Λ–c Sum of all exclusive contributions • Only small room for unaccounted contributions • Charm strange final states • Limited inclusive data above 4.5 GeV • Charm baryons final states Галина Пахлова

  37. S.Godfrey, arXiv:0910.3409 [hep-ph] How to fit measured cross section? Four (five?) ψ states, five (three?) Y states and at least 11 open charm thresholds! Галина Пахлова

  38. arXiv:0801.3418 Cornell Coupled Channel model: R in the threshold region E.Eichten QWG08 • Complicated thresholds behaviour • Need improved model to describe standard and to search for new states Галина Пахлова

  39. c c In conclusion Галина Пахлова

  40. Experiment Six exclusive open charm final states are measured DD, D*D, D*D*, DDπ, DD*π, ΛcΛc • Their sum is close to e+e– → hadrons • Belle & BaBar & Cleo cross section measurements are nicely consistent with each other • In charm meson final states no evident peaks corresponding to members of charmoniumlike 1– –family are found ! • ΛcΛc • enhancement at threshold, quantum numbers, mass and width are consistent with Y(4660) • Various interpretations ... it’s time to describe these data by realistic common fit and to extract realistic parameters of ψ states ... Галина Пахлова

  41. All presented cross sections can be found in Durham Data Base Theoretical efforts to describe charm components of inclusive cross section are kindly requested! Галина Пахлова

  42. Спасибо Галина Пахлова

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