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Stephen Olsen U. of Hawai’i & 高能所 北京

X. YZ. Mesons. e otic. Stephen Olsen U. of Hawai’i & 高能所 北京. Sookyung Choi Scientist of the month Aug 2004, Korea. Constituent Quark Model (CQM). Gell-Mann. (& 6 antiquarks). 6 quarks. Zweig. u -2/3. c -2/3. t -2/3. u +2/3. c +2/3. t +2/3. b +1/3. s +1/3. d -1/3.

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Stephen Olsen U. of Hawai’i & 高能所 北京

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  1. X YZ Mesons e otic Stephen Olsen U. of Hawai’i & 高能所 北京 Sookyung Choi Scientist of the month Aug 2004, Korea

  2. Constituent Quark Model(CQM) Gell-Mann (& 6 antiquarks) 6 quarks Zweig u-2/3 c-2/3 t-2/3 u+2/3 c+2/3 t+2/3 b+1/3 s+1/3 d-1/3 s-1/3 b-1/3 d+1/3 Baryons: qqq Mesons: q q c+2/3 s+1/3 Wc: u+2/3 s-1/3 B+ : b+1//3 C-2/3 S=1/3 u-2/3 Wc: B- : s+1/3 b-1/3

  3. Fabulously successful mesons q q

  4. Are there other color-singlet arrangements? Pentaquarks: e.g. an S=+1 baryon (only anti-s quark has S=+1) Glueballs: gluon-gluon color singlet states Multi-quark mesons: qq-gluon hybrid mesons Non-quark model states expected in QCD d u u d s u c u c c c

  5. Our approach:look for non-qq mesons 4 (& 6) quark states d u u c u d u u c u “hybrid” qq-gluon states c c

  6. Beijing Spectrometer (BES)

  7. J/y g pp g c+2/3 p C-2//3 u+2/3 u+2/3 d-1/3 p u-2/3 u-2/3 d+1/3

  8. J/y g pp What is this??? This is the hcpp J.Z. Bai et. al (BES). PRL 91, 022001 (2003) M(pp) GeV

  9. Fit the M(pp) distribution M=1835 MeV no know G  100MeV resonance Best fit to this peak is a resonance with peak mass below the pp mass threshold

  10. A pp bound state (baryonium)? There is lots & lots of literature about this possibility deuteron: baryonium: attractive nuclear force attractive force? p n p p loosely bound 3-q 3-q color singlets with Md = 2mp- e loosely bound 3-q 3-q color singlets with Mb = 2mp-d ?

  11. Expectation for pp bound state meson below-threshold p and p annihilate to mesons Above threshold Xpp ~100% I=0, JPC=0-+ init. state: pp p+p-h’ is common mp +mp

  12. Look in J/y g p+p-h’ mp+mp M=1833 MeV G  70MeV M(p+p-h’)

  13. X(1835): “6-quark” meson? d u 3 quarks + u u u 3 antiquarks d • Need to confirm JPC of the p+p-h’ peak is 0-+ • Need to find it in other common 0-+ pp annihilation channels jobs for BESIII

  14. Charmonium is of particular interest because it is an especially good system to use to search for non-qq mesons

  15. a cc meson has to fit into one of these slots: If it doesn’t, it is a good candidate for a non qq meson

  16. B-factories produce lots of cc pairs 0-+, 1-- or 1++ 0-+, 0++, 2++ 1-- only C =+ states

  17. Lots new on the “XYZ” particles Status spring 2007: New Belle/BaBar results: (Summer 2007) • X(3872) • p+p- J/y in BKp+p-J/y • Z(3930) • DD in gg DD • Y(3940) • wJ/y in BK wJ/y • X(3940) • e+e-J/y X & e+e-  J/y DD* • Y(4260) • p+p-J/y in e+e-g p+p- J/y • Y(4325) • p+p-y’ in e+e-g p+p-y’ X(3880)DD - e+e-  J/y DD confirmed by BaBar updated by Belle Y(4008)? X(4160)D*D* - e+e-  J/y D*D* Y(4250) Y(4370) Z+(4430)p+y - BKp+y’ Y(4660)

  18. I’ll concentrate on recent results.

  19. X(3872) S-K Choi, SL Olsen et al,

  20. X(3872) properties (PDG2007) MeV MD0 + MD*0 = 3.871.8 ± 0.4

  21. M(pp) looks like rpp CDF Belle PRL 96 102002 c2/dof = 43/39 (CL=28%) kinematic limit≈mr • Belle & CDF: JPC = 1++ most likely

  22. What’s new with the X(3872)? BaBar confirms Belle’s DDp threshold enhancement Both groups see a high mass value Mass is 3.8±1.2 MeV above WAvg X(3872)ppJ/y mass; (~3s) is this significant?

  23. Belle’s BKSX & BK±X comparison Confirms an earlier BaBar result KS mode K± mode “molecular” models predicted this to be <<1 (Braaten et al PRD 71 074005) DM = 0.22 ± 0.90 ± 0.27 MeV “diquark-antidiquark” models predicted this to be 8±3 MeV (Maiani et al PRD 71 014028)

  24. Is there a cc slot for the X(3872)? 1++(cc1’) 3872 • Br(gJ/y) too small • Br(rJ/y) too big 2-+(hc2) • hc2rJ/y ispin forbidden • D0D0p0 @ thresh.suppressed • BKcc(J=2) suppressed

  25. Y(3940) in BK wJ/y S-K Choi, SL Olsen et al, Belle PRL94, 182002 (2005) M≈3940 ± 11 MeV G≈ 92 ± 24 MeV M2(wJ/y) GeV2 M2(Kw) GeV2 M(wJ/y) MeV

  26. Y(3940) properties G(Y3940 wJ/y)> 7 MeV (an SUF(3) violating decay) ~ this is 103 x G(y’  hJ/y) (another SUF(3) violating decay) M(wJ/y) MeV if the Z(3930) is the cc2’ the Y(3940) mass is too high for it to be the cc1’ Belle PRL94, 182002 (2005)

  27. Confirmed by BaBar this summer G.Cibinetto EPS-2007 B±K±wJ/y B±K±wJ/y B0KSwJ/y M2(Kw) ratio M(wJ/y) Some discrepancy in M & G; general features agree

  28. Is there a cc slot for Y(3940) ? hc” Mass is low cc1’ Can M(cc1’)>M(cc2’)? 3940 3931 cc0’ “ “ “ “ For any charmonium assignment, G[Y(3940)w J/y] is too large.

  29. The 1-- states seen in ISR y (y’)

  30. 233 fb-1 e+e- gisr Y(4260) at BaBar BaBar PRL95, 142001 (2005) fitted values: M=4259  8 +2 MeV G = 88  23 +6 MeV -6 -9 Y(4260) ~50pb

  31. Not seen in e+e- hadrons ~3nb 4260 speak(Y(4260)+p-J/)~50 pb Huge by charmonium standards BES data 4260 G(Y4260p+p- J/y) > 1.6MeV @ 90% CL X.H. Mo et al, PL B640, 182 (2006)

  32. “Y(4260)” at Belle (New) BaBar values: M=4247  12 +17 MeV G = 108  19 ±10 MeV -32 M=4259  8 +2 MeV G = 88  23 +6 MeV -6 -9 M=4008  40 +114 MeV G = 226  44 ±87 MeV -28 ??? Resonance? Thresh effect? …? C.Z Yuan et al (Belle) arXiv:0707.2541 To appear in PRL

  33. No 1-- cc slot for the Y(4260) X.H. Mo et al, hep-ex/0603024 4260 4260

  34. Is the Y(4260) a cc-gluon hybrid? c c • qq-gluon excitations predicted 30 yrs ago • lowest 1-- cc-gluon mass expected at ~4.3 GeV • relevant open charm threshold is D**D (~4.28 GeV) • G(ppJ/y) larger than that for normal charmonium • G(e+e-) smaller than that for ordinary charmonium Horn & MandulaPRD 17, 898 (1977) Y(4260) seems to match all of these!!! Banner et al, PRD 56, 7039 (1997); Mei & Luo, IJMPA 18, 15713 (2003) Isgur, Koloski & Paton PRL 54, 869 (1985) McNeile, Michael & Pennanen PRD 65, 094505 (2002) Close & Page NP B443, 233 (1995)

  35. DD** thresholds in & “Y(4260)” D2D D** spectrum D1D No obvious distortions 4.28-mD M(p+p-J/y) GeV

  36. BaBar’s p+p-y’ peak at 4325MeV D2D 298 fb-1 (BaBar) hep-ex/0610057 e+e-gISRp+p-y’ D1D Nevt = 68 (<5.7 GeV/c2) Nbkg = 3.1 1.0 M=4324  24 MeV G = 172  33 MeV above all D**D thresholds Not Compatible with the Y(4260) BaBar PRL 98 252001 (2007) S.W.Ye QWG-2006 June 2006

  37. 4325 MeV p+p-y’ peak in Belle (new) Two peaks! (both relatively narrow) (& both above D**D thresh) (& neither consistent with 4260) M=4361  9 ±9 MeV G = 74  15 ±10 MeV M=4664  11 ±5 MeV G = 48  15 ±3 MeV 4260 BaBar values M=4324  24 MeV G = 172  33 MeV X.L. Wang et al (Belle) arXiv:0707.3699 548 fb-1

  38. Latest News electrically charged!! S-K Choi, SL Olsen et al, Belle, submitted to PRL

  39. M(p±y’) from BK p± y’ M = 4433 ±4 ±1 MeV Gtot = 45 +17+30 MeV Nsig =124 ± 31evts K*Kp Veto Veto K2*Kp? -13 -11 M2(py’) GeV2 6.5 M(py’) GeV M2(Kp) GeV2 K. Abe et al (Belle) arXiv:0708.1790

  40. Comments on the Z+(4430) Not a reflection from the Kp system ~ No significant signal in B KpJ/y It has non-zero charge  not cc or hybrid Mass, width & decay pattern similar to Y(4360) & Y(4660)

  41. (mine) conclusions • There seems to be a new hadron spectroscopy in the M=3.5~5 GeV region • Maybe more than one • Bodes well for BESIII, Super-B factories & PANDA • Some states are narrow even though they are far above decay thresholds • e.g. Y(4660)ppy’ & Z+(4430)p+ y’ have large Q but G≈50 MeV • characterized by large partial widths (Bfs) to hadrons+J/y (or y’) • Br(X(3872)rJ/y) > 4.3% (Isospin=1) • G(Y(3940)wJ/y) > 7 MeV (SU(3) octet) • G(Y(4260)p+p-J/y) > 1.6 MeV • States that decay to y’ not seen decaying to J/y (and vice-versa) • Bf(Y(4660)ppy’) >> Bf(y(4660)ppJ/y)  same for Y(4360) & Z(4430py’ • Y(4260) not seen in Y(4260)ppy’ • The new 1-- states are not apparent in the e+e-D(*)D(*) cross sections • There is no evident transitions at the D**D mass threshold

  42. New 1-- states p+p- J/y p+p-y’ K+K- J/y

  43. DD thresholds DSDS thresholds some of the states are near thresholds, but this is not a universal feature

  44. stot Y(4360) Y(4660) Y(4008) DD None of the 1--peaks matchstructures in e+e- hadrons D*D* DD* Y(4260) Pakhlova (Belle) PRL 98, 092001 (2007)

  45. Lots of pieces Y(3940) Z(4430) X(3940) Are they all from the same puzzle? X(4160) Y(4660) Y(4008) Y(4260) Y(4360) X(3872)

  46. 謝謝

  47. Actual fit fitted peak location J/ygpp in the BES expt M=1830.6± 6.7 MeV/c2 G < 153 MeV/c2 (90% CL) c2/dof=56/56 0 0.1 0.2 0.3

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