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Exotic charmonium-like states in B decays PowerPoint Presentation
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Exotic charmonium-like states in B decays

Exotic charmonium-like states in B decays

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Exotic charmonium-like states in B decays

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  1. ITEP Seminar, 18 Nov 2009 Exotic charmonium-like states in B decays Roman Mizuk, ITEP

  2. Conventional Charmonium in Quark Model c c Above open charm threshold broad states are expected n(2S+1)LJ n radial quantum number J = S + L P = (–1)L+1parity C = (–1)L+Scharge conj. Below open charmthreshold most states are narrow

  3. B-factories e+e–→(4S) and nearby continuum: Ecms ~ 10.6 GeV L ~ 1034/cm2/s 950 + 530 fb-1 in total

  4. cc production at B factories

  5. Outline • X(3872) • States near 3940 MeV • Z(4430) and Z1(4050) & Z2(4250)

  6. Reconstruction of B decays • In (4S) decays B are produced almost at rest. • ∆E = Ei - ECM/2Signal peaks at 0. • Mbc = { (ECM/2)2 - (Pi)2}1/2Signal peaks at B mass (5.28GeV). B0J/ KS ∆E, GeV Mbc, GeV

  7. CP X(3872) B→Xsγ 479 Belle citation count 451 330 Phys.Rev.Lett.91262001, (2003) 6th anniversary!

  8. Swanson, CharmEx09

  9. pp collisions PRL91,262001 (2003) X(3872) was observed by Belle in ′ B+ → K+ X(3872) → J/ψπ+π- X(3872) Confirmed by CDF, D0 and BaBar. …recent signals of X(3872) → J/ψπ+π- B+ → K+ X(3872) PRL103,152001(2009) PRL93,162002(2004) arXiv:0809.1224 PRD 77,111101 (2008)

  10. Mass & Width M = 3871.550.20 MeV,Γ < 2.3 MeV (90% C.L.) Close to D*0D0 threshold: m = -0.250.40 MeV.

  11. Branching Fraction PRL96,052002(2006) B K Xcc studied using missing mass technique. reconstructed K Xcc B missing mass (4S) reconstructed B 90%C.L. Br(X(3872)  J/+ -) > 2.5%

  12. Radiative Decays & J/ hep-ex/0505037 J/  CX = +1 PRL102,132001(2009) ′ J/ m (J/), MeV m (′), MeV Evidence for X(3872) → J/+-0 hep-ex/0505037 M(+-0) is peaked at kinematic boundary subthreshold production of  +-0 also CX = +1

  13. +- system from X(3872)  J/+- B(X(3872)  J/) B(X(3872)  J/) ~1 CX = + C(+-) = – (|+1,-1– |-1,+1) ( r ) Isospin (+-) = 1 L(+-) = 1 +- system has IJPC quantum numbers of 0. Mass of +- PRL96,102002(2006) hep-ex/0505038 L=0 L=1 M (+-) is well described by 0→+- (CDF: + small interfering →+-).  Large isospin violation.

  14. Spin & Parity PRL98,132002(2007) Angular analyses by Belle and CDF excluded JP = 1++ 0++, 0+-, 0-+,1-+ ,1+-, 1--, 2++, 2-- , 2+-, 3--, 3+- 2-+ 1-- 0++ Only two possibilities JP =1++ and 2-+. 2-+ is disfavored by Observation of D*D decay  centrifugal barrier at the threshold Br(X → ′ γ) / Br(X → J/γ) ~3multipole suppression 1++ are favorite quantum numbers for X(3872) 2-+ is not excluded.

  15. B K D0D*0 D*→Dγ PRL97,162002,2006 6.4σ D*→D0π0 605 fb-1 B K D0D00 1.4σ PDG Flatte vs BW similar result: 8.8σ New Belle vs. BaBar: ~2σ difference PRD77,011102,2008 B+& B0D0D*0K 4.9σ 347fb-1 arXiv:0810.0358 X(3875)  X(3872)?

  16. X(3872) Experimental Summary Br(X  D*0D0) Br(X  J/+-) ~10 JPC = 1++ (2-+ not excluded) MJ/ = 3871.550.20 MeV Γ < 2.3 MeV (90% C.L.) Close to D*0D0 threshold: m = -0.250.40 MeV. Decay modes: Br(X(3872)  J/0) > 2.5% J/ J/ J/  D*0D0 0.14  0.05

  17. Interpretation: Charmonium? 3872 JPC = 1++c1′ (23P1) • Γ (c1′→ J/ψγ) / Γ (c1′→ J/ψπ+π-) • expect 30 • measure 0.140.05 JPC = 2-+ηc2 (11D2) Expected to decay into light hadronsrather than into isospin violating mode.  X(3872) is not conventional charmonium.

  18. Tetraquark? PRD71,031501,2005 B0 B- X(3872)– X(3872)– M(J/π–π0) M(J/π–π0) PRD71,014028(2005) Maiani, Polosa, Riquer, Piccini; Ebert, Faustov, Galkin; … [cq][cq] Charged partners of X(3872) should exist. Two neutral states ∆M=(83)MeV,one populate B+ decay, the other B0.  No evidence for X–(3872)  J/–0 excludes isovector hypothesis

  19. B0 vs. B+ B0→XK0s 5.9 M(J/) arXiv:0809.1224 605 fb-1 PRD 77,111101 (2008) [413 fb-1] = (2.7 ± 1.6 ±0.4) MeV 2.3σ M(J/) No evidence for X(3872) neutral partner in B0 decay.

  20. Two overlapping peaks in J/+- mode? PRL103,152001(2009) No evidence for two peaks m < 3.2 MeV at 90% C.L. Tetraquarks are not supportedby any experimental evidence for existence of X(3872) charged or neutral partners.

  21. March 1976 MX = 3871.55  0.20 MeV (MD*0 + MD0) = 3871.80  0.35 MeV BES III can improve on this November 1976 D0D*0 molecule? Swanson, Close, Page; Voloshin; Kalashnikova, Nefediev; Braaten; Simonov, Danilkin ... m = -0.250.40 MeV Weakly bound S-wave D*0D0 system D*0D0 molecule can reconcile X(3872) signals in D*0D0 and J/+- modes. Bound state Virtual state D0D00 If EX goes positive … J/+- D0D00 J/+- D*0D0

  22. B(X(3872)  J/) B(X(3872)  J/) ~1 B(X(3872) ) B(X(3872)  J/) ~3 D0D*0 molecule Large isospin violation due to 8MeV differencebetween D*+D- and D*0D0 thresholds. Similar ratio is expected for c1 decays c1 admixture? Large production rate in B decays and at TEVATRON c1? Bound or virtual? c1 admixture? Analysis of data Yu.S.Kalashnikova, A.V.Nefediev arXiv:0907.4901 Belle data: bound state with ~ 30% admixture of c1. BaBar : virtual state with ~ no c1 admixture. ~2 difference  Present statistics is insufficient to constrain theory?

  23. There are other similar analyses which differ in the fit functions: Braaten, Stapleton Zhang, Meng, Zheng arXiv: 0907.3167 0901.1553 Steve Olsen “Charmed Exotics 2009”  theorists here should agree on the proper form & then experimenters should use it in a proper unbinned fit

  24. B  K  X(3872) ~90 events arXiv:0809.1224 605 fb-1 Very weak K*(892) bg signal Br(BJ/ K*0) Br(BJ/ KNR) ~4

  25. DD* molecular models for the X(3872) attribute its production & decays  charmonium to an admixture of c1′ in the wave fcn. But BKX(3872) is very different from BK charmonium. KX3872 Kc1 K′ Belle arXiv 0809.0124 Belle arXiv 0809.0124 Belle PRD 74 072004 M(K) M(K) KJ/ Kc M(K) Belle F.Fang Thesis BaBar PRD 71 032005 M(K) M(K)

  26. States near 3940 MeV

  27. The states near 3940 MeV-circa 2005- Z(3930) X(3940) Y(3940)  DD e+e- J/ DD* BKJ/ Probably the c2’ M(J/) M(DD) M(DD*) M = 3929±5±2 MeV tot = 29±10±2 MeV Nsig =64 ± 18evts M≈3940 ± 11 MeV ≈ 92 ± 24 MeV M = 3942 +7± 6 MeV tot = 37 +26 ±12 MeV Nsig =52 +24 ± 11evts -6 -15 -16 PRL 96, 082003 PRL94, 182002 (2005) PRL 100, 202001

  28. Y(3940)  DD* ? BKDD* 3940 MeV 3940 MeV

  29. X(3940)J/? e+e-J/ + ( J/) PRL 98, 082001

  30. X(3940) ≠ Y(3940) @ 90% CL

  31. Y(3940) confirmed by BaBar B±K±J/ B0KSJ/ ratio J) PRL 101, 082001 Some discrepancy in M & ; general features agree

  32. Belle-BaBar direct comparison Same binning (Belle published result : 253 fb-1) 492fb-1 Belle will update with the complete (4S) date set later this Fall

  33. Y(3915)J/ from Belle M: 3914  3  2MeV, : 23  10 +2-8 MeV, Nres = 55  14 +2-14 events Signif. = 7.7, 7.7 preliminary Probably the same as the Belle/BaBar Y(3915)

  34. cc assignments forX(3940) & y(3915)? _ c’’’ c” c0’ 3940MeV 3915MeV • Y(3915) = co’? (J/) too large? • X(3940) = c”?  mass too low?

  35. Z(4430) and Z1(4050) & Z2(4250) Smoking guns for charmed exotics: u c c d

  36. BK ’ (in Belle) M2(+’) ?? K*(1430)K+-? K*(892)K+- M2(K+-)

  37. The Z(4430)± ±’ peak BK+’ evts near M(’)4430 MeV M() GeV M2(±’) GeV2 Z(4430) M(±’) GeV   M2() GeV2 “K* Veto”

  38. Shows up in all data subsamples

  39. Could the Z(4430) be due to a reflection from the K channel?

  40. Cos  vs M2(’)   ’ K +1.0 22 GeV2 (4.43)2GeV2 0.25 M2(’) cos 16 GeV2 -1.0 M (’)& cosare tightly correlated; a peak in cos peak in M(’)

  41. S- P- & D-waves cannot make a peak (+ nothing else) at cos≈0.25 not without introducing other, even more dramatic features at other cos (i.e., other M’) values.

  42. But…

  43. BaBar doesn’t see a significant Z(4430)+ “For the fit … equivalent to the Belle analysis…we obtain mass & width values that are consistent with theirs,… but only ~1.9s from zero; fixing mass and width increases this to only ~3.1s.” Belle PRL: (4.1±1.0±1.4)x10-5

  44. Reanalysis of Belle’s BKpy’ data using Dalitz Plot techniques

  45. 2-body isobar model for Kpy’ Our default model K*y’ B K2*y’ Kpy’ KZ+

  46. Results with no KZ+ term 2 1 3 1 2 4 5 C B A 3 4 A B 5 C fit CL=0.1% 51

  47. Results with a KZ+ term 2 1 B 2 3 4 5 A 1 3 4 C B C A 5 fit CL=36%

  48. Compare with PRL results K* veto applied With Z(4430) Signif: 6.4s Published results Without Z(4430) Mass & significance similar, width & errors are larger BaBar: Belle: = (3.2+1.8+9.6 )x10-5 0.9-1.6 No big contradiction

  49. Variations on a theme Z(4430)+ significance Others: Blatt f-f term 0r=1.6fm4fm; Z+ spin J=0J=1; incl K* in the bkg fcn

  50. The Z1(4050)+ & Z2(4250)+p+cc1 peaks PRD 78,072004 (2008)