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  1. Near-threshold non-qq meson candidates _ Stephen Lars Olsen Seoul National University Heavy-Quark Hadrons at J-PARC Symposium at Tokyo Inst. Tech., June 22,2012

  2. Constituent Quark Model Gell-Mann 1964 The model was proposed independently by Gell-Mann and Zweig with three fundamental building blocks: 1960’s (p,n,l) Þ 1970’s (u,d,s mesons are bound states of a of quark and anti-quark: Zwieg baryons are bound state of 3 quarks:

  3. Fabulously successful Quarks are probably the most well known particle physics quantity among the general public Google Search: quark: 41,000,000 results (0.13 seconds) 鈴木 一朗: 2,600,000 results (0.65 seconds)

  4. Superseded by QCD in the 1970s:observed particles are color singlets color + complementary color  white white 3 primary colors  blue-yellow green-magenta red-cyan Λ= (uds) Mesons are color-anticolorpairs Baryons are red-blue-green triplets 4

  5. QCD has other color-singlet combinations: Pentaquark: H-diBaryon Glueball Tetraquark mesons qq-gluon hybrid mesons Other possible “white” combinations of quarks & gluons: u d u d s _ u tightly bound 6-quark state S=+1 Baryon d s u s d Color-singlet multi- gluon bound state D0 _ c _ u loosely bound meson-antimeson “molecule” c tightly bound diquark-diantiquark u _ p _ u c _ _ u _ D*0 c _ _ c c

  6. Where are they? u d u d s _ u d s u s d D0 _ c _ u c _ p u _ _ c c u c _ _ u _ D*0 c

  7. some history: low-mass scalar mesons the “light” scalar-meson nonet JP=0+ 800 800 k+ k0 The “light” scalar mesons 980 980 a00 f0 a0- a0+ 980 s 600 _ k- k0 800 800 More “light” scalar-mesons than quark model slots: s, f0(980), f0(1370), f0(1500), f0(1710), f0(1790), …

  8. light scalar nonet: masses are inverted scalars pseudoscalars unique typical ss-quark content _ • In qq meson nonets, the I=1 state (here the a0(980)) has no ss content. • No “light” JP=1+ and 2++ partner nonets in the same mass range. _ _

  9. If not qq, then what? _ Possibilities that have been suggested: loosely bound meson-antimeson “molecule” tightly bound diquark-diantiquark _ _ s K q _ q s “nuclear” force _ s q _ s In color space: _ q s K red+blue=magenta (antigreen) cyan+yellow=green (antimagenta) J.D.Weinstein & N.Isgur PRD 27, 588 (1983) A colored diquark is like a antiquark A colored diantiquark is like a quark R.L.Jaffe PRD 15, 267 (1977)

  10. Institute of High Energy Physics-- Beijing -- BEPC BESIII To Tiananmen Square (~10 km)

  11. BEPCII storage rings Beam energy: 1.0 - 2.3 GeV Peak Luminosity: Design:1×1033 cm-2s-1 Achieved:0.65x1033cm-2s-1 Beam energy measurement: Using Compton backscattering technique. Accuracy: dEbeam/Ebeam ≈ 510– 5 dEbeam ≈ 50 KeV @Ebeam ≈ mt

  12. BESIII Collaboration Helmholtz Institute Mainz Johannes Gutenberg-University Mainz 11 Turkey: Turkish accelerator center 29 >300 physicists 49 institutions from 10 countries

  13. _ The a0(980) & f0(980) straddle the KK threshold a0(980) (hp0) f0(980)  K+K- f0(980)  p+p- 2mK 2mK

  14. a0(980)0 f0(980) mixing N.N. Achasov, S.A. Devanin & G.N. Shestakov, Phys. Lett. B88, 367 (1979) isospin violation enhanced by K0 – K+ mass difference 2mK+= 987.4 MeV 2mK0= 995.2 MeV PDG2010: Mf0= 980 ± 10 MeV f0= 40 ~ 100 MeV Ma0= 980 ± 20 MeV a0= 50 ~ 100 MeV 2mK+ expect a narrow line shape: G≈2(mK0-mK+)=7.8 MeV 2mK0

  15. BES study of a0(980)0 f0(980) mixing BESIII PRD 83, 032003 (2011)

  16. a0(980)0 f0(980) mixing results _ KK molecule model 90% CL upper limits different models & parameterizations Statistics limited, but BESIII already has lots more data.

  17. J/f0(980)p0,f0(980)pp BESIII PRL 108, 182001 (2012) from helicity analyses h(1405) h(1405) f0(980)+- f0(980)00 f1(1285) 3.7s f1(1285) 1.2s 1st observations: (1405)f0(980)p0 & J/ygf0(980)p0 Large Isospin violations:

  18. Anomalous f0(980)lineshapein h(1405)f0(980)p0 BESIII PRL 108, 182001 (2012) • Fitted mass: • M”f0”= 989.9 ± 0.4 MeV • ”f0”= 9.5± 1.1 MeV The peak is midway between 2mK0 & 2mK+ • & width ≈ 2(mK0 - mK+) PDG2010: Mf0= 980 ± 10 MeV • f0=40 ~ 100 MeV

  19. Effect of Triangle Singularity? J.J.Wu et al, PRL 108, 081803 (2012) Triangle Singularity (TS) a0—f0 mixing h(1405) _ _ K*K and KK are on shell enhancing TS contribution and isospin violation a0—f0 mixing is too small to explain anomaly by itself f0(980) and h(1405) strongly influenced by the nearby KK & KK* thresholds. _ _

  20. Baryonium at the pp threshold? _

  21. J/ygpp @BESII What is this??? BESII PRL 91, 022001 (2003) This is the hcpp the J/y’s spin=0 partner M(pp) GeV

  22. Fit the M(pp) distribution _ fit with a sub-threshold resonance “cartoon” real fit 0.3 0.2 0.1 0 M(pp) GeV Mpp-2mp (GeV) BESII PRL 91, 022001 (2003) +3 +5 -10 -25 M=1859 MeV/c2 G < 30 MeV/c2 (90% CL)

  23. X(1835) has large BR to pp • BESIII: • our estimate from unpublished Crystal Ball data: • implies a huge Br(Xpp): J/yg X XtalBall (unpublished) see L.Kopke, N.Wermes,Phys. Rep 174, 67 (1989) Since decays to pp are only possible from the tail of X(1835), such a BR indicates X(1835) has a huge coupling to pp !

  24. X(3872) meson near the DD* threshold _

  25. KEK Laboratory, Tsukuba Japan Belle Detector Fukushima Mt Tsukuba e- e+ KEKB

  26. _ cc meson production in B decays C+2/3 “Charmonium” _ b-1/3 C-2/3 B0 W- d1/3 _ S-1/3 “spectator” K0 d1/3 Belle’s main purpose: Measure CP violations with B mesons that decay like this.  Nobel prize for Kobayashi &Maskawa in 2008

  27. _ Charmonium (cc) meson spectrum All of the states below 2mD have been identified

  28. The X(3872) in BK p+p-J/y discovered by Belle (140/fb) PRL 91, 262001 (2003) y’p+p-J/y X(3872)p+p-J/y M(ppJ/y) – M(J/y)

  29. X(3872)p+p-J/y confirmed by many experiments LHCb Belle CDF ~6000 evts! MX = 3871.61 ± 0.16 ± 0.19 MeV MX = 3871.96 ± 0.46 ± 0.10 MeV CDF: PRL 103 152001 MX = 3871.85 ± 0.27 ± 0.19 MeV LHCb: arXiv:1112.5310 Belle: PRD 84 052004

  30. p+p-system in X(3872)p+p-J/y comes from rp+p- Belle: PRD 84 052004 CDF: PRL 96 102002 rp+p- lineshape M(p+p- ) p+ r p- X3872 J/y Problem: (cc)r J/y violates Isospin and should be strongly suppressed _ M(p+p- )

  31. X(3872) not well matched toany unassigned cc level _ 3872 MeV

  32. X(3872) mass(in p+p-J/ychannel only) D0D*0 molecule?? _ D0 _ c u _ p _ _ u D*0 c If so, the binding energy is very small Isospin Violation in X(3872) decay: • MD0+MD*0=3871.79 ± 0.30 MeV MX(3872) –(MD0 + MD*0) = -0.12 ± 0.35 MeV _ ≈on mass shell ≈8MeVoff mass shell MX(3872) –(MD+ + MD*-)= -7.74 ± 0.35 MeV

  33. X(3872)-J/y relative sizes drms(208Pb nucleus)≈5.5 fm + + + X(3872) + + 208Pb + + drms(X3872) ~ 8 fm + + + + + + + + + drms(J/y) ≈ 0.4 fm + + + J/y Volume(J/y) /Volume(X3872) ≈ 10-4 • How can such a fragile object be produced in H.E. pp collisions? heavy ion collisions?? _ -- arXiv 0906.0882: sCDF(meas)>3.1±0.7nb vsstheory(molecule)<0.11nb C. Bignaminiet al, PRL 103, 162001:

  34. Very different objects! Sun Venus (x3)

  35. Charged Zb1(10,610)+ and Zb2(10,650)+ in the b-quark sector

  36. “bottomonium” bb mesons _ ϒ(4S) 2MB = 10358.7 MeV (4S) p+p-  (1S) ?

  37. Belle: G(4S)p+p-(1S) (4S)  (1S) p+p- 2S 3S 4S 477 fb-1 52±10 evts Belle: PRD 75 071103

  38. (5S) p+p-  (1S) ? ϒ(5S) ϒ(4S) 2MB = 10358.7 MeV

  39. Belle:G(5S)p+p-(1S) ~1/20th the data ~1/5ththe cross-section 23.6 fb-1 vs 477 fb-1 325±20 evts! K.F. Chen et al (Belle) PRL 100, 112001 (2008)

  40. “(5S)” is very different from other  states Anomalous production of (nS)+- (MeV) Belle PRL100,112001(2008) X10--2 Recall Y(4260) with anomalous (J/+-) Is there a Yb equivalent close to (5S)

  41. + “Y(5S)” p-Zb1,2 p+ϒ(1,2,3S) p- Zb2(10660) Zb1(10610) p+ 10,660 MeV 10,610 MeV p+ ϒ(3S) p+ ϒ(2S) ϒ(1S) M(Υ(nS)π+)max

  42. + “Y(5S)” p-Zb1,2 p+hb(1,2P) p- Zb2(10660) Zb1(10610) p+ 10,660 MeV 10,610 MeV p+ hb(2P) hb(1P) M(hb+)

  43. Summary of parameter measurements mB+mB* 2mB* Zb(10610) Zb(10650) M=10607.22.0 MeV M=10652.21.5 MeV =18.42.4 MeV =11.52.2 MeV March 2012 Belle PRL 108, 122001

  44. Zb1 & Zb2, “smoking guns” for multiquark mesons u b • decays to ϒ(nS) & hb(nP)  must contain bb pair • electrically charged  must contain ud pair _ b d _

  45. _ _ B-B* & B*-B* molecules?? B Zb(106050)± Zb(106010)± B* b b b _ _ b _ _ B* B* _ _ B-B* “molecule” B*-B* “molecule” MZb(106010) –(MB+MB*) = + 3.6 ± 1.8 MeV MZb(106010) –2MB* = + 3.1 ± 1.8 MeV Slightly unbound threshold resonances?? M=10608.11.7 MeV M=10653.31.5 MeV Belle: =15.52.4 MeV =14.02.8 MeV MB* + MB* = 10650.2  1.0 MeV PDG: MB + MB* = 10604.50.6 MeV

  46. Summary Lots of new particles & threshold effects found recently • KK/KK* thresholds have large influences on f0/a0(980) & h(1405) • X(1860) near NN threshold pp bound state (baryonium)? • X(3872) near DD* threshold  D0D*0 bound state? • Zb1(10,610) * Zb2(10660)  BB* & B*B* resonances? _ _ _ _ _ _ _ _ Lots of work for theorists to do…

  47. Thank you どもぅありがとぅ 감사합니다

  48. mesons come in nonets JP=0- JP=1- 498 494 892 896 K*+ K*0 135 548 783 776 776 776 r- w r0 r+ 139 139 958 f 1020 _ 494 498 K*- K*0 896 892 (p+,p0,p-)=lightest (r+,r0,r-)=lightest nr=0 nr=0 S-wave S-wave

  49. baryons come in octets & decuplets JP=1/2+ JP=3/2+ 939 938 M=1232 MeV 1115 M=1385 MeV 1189 1197 1192 M=1533 MeV 1315 1321 ?? W- M=1672 MeV M=????MeV all nr=0 all S-waves all nr=0 all S-waves

  50. W- not the 1st Baryon correctly predicted 1959!! pg 425 R. Dalitz 1925-2006 S.F. Tuan KN threshold 1405 MeV