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Exotic states with cc

Exotic states with cc. Riccardo Faccini University “La Sapienza” and INFN Rome FPCP 2009 31 May 2009 Lake Placid, NY, USA. Quarkonium for Pedestrians. Quarkonium is a bound state of a quark and an antiquark Relevant quantum numbers: n,L,S,J Relationship with Parity and Charge Conj:

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Exotic states with cc

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  1. Exotic states with cc Riccardo Faccini University “La Sapienza” and INFN Rome FPCP 2009 31 May 2009 Lake Placid, NY, USA

  2. Quarkonium for Pedestrians • Quarkonium is a bound state of a quark and an antiquark • Relevant quantum numbers: n,L,S,J • Relationship with Parity and Charge Conj: • P=(-1)L+1, C=(-1)L+S • Not all JPC allowed (e.g. 0+-,0--,1-+,2+- forbidden) • Decay Properties: • Below open quark threshold (e.g. (cc)DD) only electromagnetic or as suppressed decays allowed  mostly narrow states • Above open quark threshold (if DD decays allowed) mostly broad states

  3. Charmonium: state of the art same JPC as J/y but mostly D wave ! (2S+1)LJ y(4160) Increasing L  M(MeV) y(4040) Open charm thr. y(3770) y’ Increasing n  h’c cc2 hc cc1 cc0 J/y hc (pot. Models) QWG: hep-ph/0412158 JPC Basically all states below the open charm threshold are observed and explained

  4. Beyond the quarkonium • Search for states with 2 quarks+”something else” • New forms of aggregation • Expected but never identified!!! • Hybrids: qq+n gluons • Lowest state 1-+ (forbidden for quarkonium) • Dominant decay HDD** • Tetraquarks: [qq’][qq’] • Large amount of states • small widths also above threshold • Molecules: M[qq]M[q’q’] • Smaller number of states but still small widths also above threshold • Search for resonances: • with non-quarkonium JPC • unnaturally small widths • not null charge: would be clear indication of something new going on

  5. Measuring the quantum numbers gISR e+ X • Production: • ISR only produces with same quantum numbers as the photon (JPC=1--) • gg only produces with C=+ • Double charmonium production e+e- g*Xcc1Xcc2 Possible only if quantum numbers of the two charmonia can be combined to give a 1--. • Decay: • Angular distributions of decay products depend on JP. • Selection rules • Conservation of J • Conservation of P,C in strong and electromagnetic decays e- e+ e+ X e- e-

  6. The new zoology X(3872) The 1-- family The charged states hot off the press

  7. X(3872): known facts • Decays • XJ/y pp (original observation) • Maybe J/y r • BF(XJ/y w)~ BF(XJ/y r) • Full angular analysis from CDF • XJ/y g Implications: • C(X)=+1 • C(pp in J/y pp decay)=-1 • I(pp)=L(pp)=1  consistent with J/yr decay hypothesis • JPC=1++ or 2-+ from angular analysis • Production • only B decays so far • No prompt e+e- production observed (BaBar arXiv:0707.1633)

  8. The X(3872) puzzle Not matching any predicted state! Above DD threshold (allowed): should have large width but it is narrow Charmonium highly suppressed decay into J/y r (isospin violation) y(4160) (2S+1)LJ Increasing L  M(MeV) Open options • DD* molecule • Right above the threshold • favors DD* decay over J/ypp over J/yg (as observed) • Tetraquark • Explains small width • Predicts a set of 4 states (2 charged and 2 neutral). • Finding these states is critical y(4040) X(3872)? Open charm thr. y(3770) Increasing n  h’c y’ cc2 hc cc1 cc0 J/y (pot. Models) hc JPC

  9. Are there two XJ/ypp ? arXiv:0807.3699 • CDF with largest sample investigates the mass distribution for two resonances closeby Fitted mass difference as a function of first gaussian fraction DM<3.2 MeV @90%C.L.

  10. arXiv:0809.1224 Is the X in B0 and B+ decays the same? B± XK± B0 XKS X  J/ypp More in Phys.Rev.D77:111101,2008 Consistent with one state, equally present in decays

  11. X(3872)D0D*0 • Belle [PRL 97, 162002 (2006)] observed X(3872)D0D0p0 • Confirmation and integration from BaBar in BDD*K[PRD 77, 011102(2008)] • Most recent result from Belle D*D0p0 D*D0g arXiv:0810.0358

  12. X(3872) mass [my extrapolation] Poor agreement among mass measurements: XJ/ypp and XDD(*) differ by ~3.5s TWO STATES? X(3872) & X(3876) ? Predicted by tetraquark model (but why so close to threshold?)

  13. The new zoology X(3872) The 1-- family The charged states hot off the press

  14. The 1-- family Several resonances observed in e+e- YgISR(certainly JPC=1--) Y(4260)J/ypp Confirmation + J/yp0p0: CLEO PRD74, 091104 (2006) CLEO-c PRL 96, 162003 (2006) A new state: Y(4260) PRL 95, 142001 (2005) Yet another state Y(4350) PRL 98, 212001 (2007) Y(4350)y(2S)pp

  15. The youngest of the 1-- family PRL99, 142002 (2007) 5.8s Present in low stat in BaBar’s publication Zoomed BaBar Yy(2S)pp

  16. Y(4260) PRL99, 142002 (2007) arXiv 0808.1543 DECAY PROPERTIES f0 dominating? Threshold effects? Y(4660) Y(4350)

  17. PRL101,172001 (2008) X(4630) [or Y(4660)?]LcLc • Y(4660) good candidate for a LcLc bound state • Search for ISR e+e- LcLcg events Right sign p CFR Wrong sign p In the discovery mode Assuming same state as y(2S)pp !

  18. ψ(3770) ψ(3770) DD DD ψ(4415) ψ(4415) ψ(4040) ψ(4040) ψ(4160) ψ(4160) G(3942) G(3942) ψ(4260) ψ(4260) D*D D*D D*D* D*D* ISR search for Y(4260)→ D(*)D(*) Y(4260) is 1-- charmonium state  should decay predominantlyto DD, D*D, and D*D* BABAR: PRD 79, 092001 (2009), 384

  19. 1-- family: recap Only seen in y(2S)pp (2S+1)LJ • Not matching any potential model prediction • Too narrow 4660 M(MeV) 4350 y(4160) 4260 y(4040) Open charm thr. y(3770) y’ “new physics”? 4260 can be fit by a tetraquark model (decaying into J/yf0 …) or a hybrid (with gpp) J/y (pot. Models) JPC 1-- 1--

  20. The new zoology X(3872) The 1-- family The charged states hot off the press

  21. The Z(4430)+ • Charged states a strong prediction of the tetra-quark model • First observed by Belle in PRL100, 142001 (2008) • Search for Z± J/y or y(2S) + p± In Byp±K decays M=4433±4±2 MeV G=45+18-13+30-13 MeV 121±30 evts , 6.5 s

  22. Criticisms to “discovery analysis” • Only “global” efficiency correction • Poor treatment of 3-body decays (cut away dominant resonances – no interference/reflections) • Arbitrary choice of background shape VETOES

  23. arXiv:0811.0564 BaBar Analysis • Event-by-event efficiency correction • Describe the Kp system in detail • Mass • Angular distributions fitted with Legendre Polynomials

  24. Comparison of BaBar background with data Same “veto” definition as Belle

  25. BaBar results • Fitting without vetoes m=4476±8 MeV/c2; Γ=32±16 MeV; signal size: 2.7σ [offset of 43±9 MeV w.r.t. Belle] • Same vetoes as Belle m=4439±8 MeV/c2; Γ=41±33 MeV; signal size 1.9σ • Conclusions: • mistreatement of background might enhance significance • veto might bias signal mass measurement

  26. arXiv:0905.2869 Belle Dalitz Plot Analysis • Belle’s observation confirmed, but errors increase • Including y(2S)W W= • m=4443+24-18 MeV • Γ=109+113-71 MeV CFR. BaBar excludes 3.1 10-5 @90%C.L.

  27. PRD 78, 072004 (2008) Z1 and Z2cc1p Same analysis strategy b+d

  28. Summary of charged states The 1– family (2S+1)LJ M(MeV) Z(4430) y(4415) y(4160) Z(4250) Z(4050) y(4040) Open charm thr. y(3770) h’c y’ cc2 hc cc1 cc0 J/y (pot. Models) hc JPC

  29. The new zoology X(3872) The 1-- family The charged states hot off the press!!

  30. The 3940 family PRL 94, 182002 (2005) PRL 96, 082003 (2006) PRL 101, 082001 (2008) PRL 98, 082001 (2007) ZDD YJ/yw XDD*

  31. New Belle peak in ggwJ/y M: 3914  3  2 MeV, G: 23  10 +2-8 MeV, Nres = 55  14 +2-14 events Signif. = 7.7s Preliminary

  32. The 4 states near 3940 Mass(GeV) Range: (s(stat.)+s(sys.)) Y(3940) Belle X(3940) Better analysis of the J/y w mass spectrum needed!! Z(3930) Good overlap with BaBar “Y(3940)” values Would allow only the 0++ assignment This X(3915) Width(GeV)

  33. Y(4140) from CDF Search for BYK YJ/yf arXiv:0903.2229 14  5events M=m(+-K+K-)-m(+-) M: 4143.0  2.9  1.2 MeV, G: 11.7 +8.3-5± 3.7MeV, Signif. > 3.8s Lowest lying hybrid, expected at m~4200MeV Possible JPC=0++,1-+,2++ Another ‘edge’ state, better candidate molecule

  34. More on the 1- - family Summary The charged candidates (2S+1)LJ M(MeV) Z(4430) y(4140) y(4415) y(4160) Z(4250) Z(4050) X(3872) never ending story y(4040) X Z Y Open charm thr. y(3770) One more member of the 3940 family h’c y’ cc2 hc cc1 cc0 J/y (pot. Models) hc X(4160) New state from CDF Good Hybrid candidate JPC

  35. Outlook Plenty of states seen with low stat and in only one channel  next generation [SuperB(elle)?] needed

  36. backup

  37. G. Cibinetto, talk at this conference Confirmation of Y(3940) (BKwJ/y) p+p-p0 BYK preliminary • New result, based on 350 fb-1: • Belle’s evidence for BYK, YJ/ confirmed • ~30MeV lower mass than Belle’s • Narrower width • Clear demonstration of decay into w • Preliminary BF estimate similar to Belle’s (~10-5) B0YKS B0/B Y(3940) closer to X(3940) Can they be the same state? Isospincons. M(J/y w) (GeV)

  38. Obtain J/yD(*)D(*)samples through kinematic separation, look at m(D(*)D(*))after background subtraction: X(4160) D*D* e+ e-J/y D(*)D(*) BELLE-CONF-0705 M = 3942 ±6 MeV tot =37 ±12 MeV Nev= 52 ±11 reconstructed Inferred (Recoil mass) Something’s here, but it’s not X(3940) 3.8  X(3940) is still there, 6.0s J/y D+ D* D*D* D Number of events M(DD) M(DD*) X(4160) claim: new state 5.5  J/y D*+ X(3940) Cross-check D* D M(D*D) M(D*D*) M = 4156 ±15MeV tot = 37 ±21MeV Nev= 24 +25 - 20 +111 - 61 One more particle to explain … JCP=0-+ not excluded (hc(3S)) +12 - 8

  39. “Just” charmonium states? (2S+1)LJ • Poor match with predictions • Above threshold? • If X≠Y, difficult to explain absence of Yopen charm • Hybrid? M(MeV) Z Y=X(3915) X Open charm thr. y(3770) h’c cc0 cc1 cc2 hc (pot. Models) JPC

  40. Fits to J/y KK invariant mass ‘Standard ‘ y(4415) + 1 BW: M = (4875±132) MeV G = (630±126) MeV single BW: M = (4430±38) MeV G = (254±49) MeV

  41. Thresholds and new states Y(4660) Y(4350) Y(4260) X(4160) XYZ(3940) X(3872)

  42. CLEO and Belle on 4260

  43. Search for X(3872)J/yg in continuum 386fb-1 arXiv:0707.1633 J/ production observed in continuum while no evidence of c states. cc1 X(3872) c1,2 or X(3872) cc2 X>2 ch c production is consistent with the expected contributions from prompty(2S) production feed-down tocc: no evidence of prompt c1,2 No evidence of X(3872) production in e+e- annihilation.

  44. Samples used in results Experiments 58MJ/y, 14M y(2S) • e+e-Charmonium (CLEO-c, BES-II) • L~1033/cm2/s • E=3.0-4.3 GeV • e+e- Y(4S): (BaBar, Belle, CLEO) • L~1034/cm2/s • Charmonium in B decays, ISR and gg production • Capability to measure JPC also in production • pp colliders (CDF, D0) • High Xsection  copious production • Extremely high backgrounds 3M y(2S), 1.8 M y(3770) 1.5M Y(1S),1.9M Y(2S), 1.7M Y(3S),9M Y(4S) 657M Y(4S) 383M Y(4S) 1.3 fb-1 2.4bf-1 • Disclamers: • time is very short •  could not cover everything • theory statements are indicative

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