1. 1 ITEP Winter School 2012, Feb 18 2012 Roman Mizuk ITEP, Moscow Quarkonium, experiment BELLE Collaboration

2. 2 Contents B-factories observed CP violation in B decays Confirmed Kobayashi-Maskawa mechanism  Nobel prize 2008 Unexpected bonus : Other highlights: many rare B decays D 0 mixing new exotic quarkonium(-like) states this lecture – experiment Mikhail Voloshyn – theory

3. 9 th anniversary! X(3872) Belle citation count B→X s γ 548 630 365 CP Phys.Rev.Lett.91 262001, (2003)

4. Outline Conventional quarkonium X(3872) 1 – – family Charged states with bb pairs _

5. Heavy quarkonium Approximately non-relativistic System Ground triplet state (v/c) 2 NameMass, MeV , MeV uu,dd  800150~1.0 ss  10004~0.8 cc  31000.09~0.25 bb  95000.05~0.08 _ _ _ _ _ Approximately non-relativistic Rich array of bound states “hydrogen atom” of QCD

6. 6 Charmonium Levels P = (–1) L+1 C = (–1) L+S S = s 1 + s 2 = {0, 1} J = S + L n – radial quantum number J PC L=0 S=0  c (1S),  c (2S) 0 – + J/ ,  (2S),  (4040),  (4415) 1 – – L=1 S=0 h c (1P) 1 + – L=1 S=1 0 + + 1 + + 2 + + 2.75 3.00 3.25 3.50 3.75 4.00 4.25 4.50 cc J/  hchc  c (2S)  (2S) L=2 S=1  (3770),  (4160) 1 – –  (3770)  (4160)  (4415)  (4040) 0 – + 1 – – 1 + – (0,1,2) ++  c2  c1  c0  c2 (2P) J PC M, GeV L=0 S=1  c0 (1P)  c1 (1P)  c2 (1P),  c2 (2P)  (3770) = 1 3 D 1 + 0.2  2 3 S 1 2M(D) n 2S+1 L J

7. 7 Bottomonium levels notation :    subscript “c”  ”b”  

8. 8 Observation of J/  p + Be → e + e - + X BNL AGSSLAC SPEARextracted 28 GeV p-beam M( e + e - ) e + e - annihilation Be target Ting et al. Richter et al. Width of t J PC =1 – – E c.m.s. , nb Mark I first 4  detector

9. 9 Observation of J/  Nov 1974 – revolution J/  is heavy and very narrow  smth new  Observation of 4 th quark  Quarks were widely recognized as particles  Beginning of modern physics

10. 10 Why J/  is so narrow?  MeV 0.093 ± 0.0020.327 ± 0.01127 ± 411 ± 127 ± 185 ± 12 J  2S cc  c0  (3770)  (4040) c c ‾ c ‾ c g g c c ‾ e, ,q  ¯ C-parity ~s~s 2/3 1/3 DD at threshold DD* D*D* For J/  strong decays are suppressed so much that EM decays are competitive. 3

11. 11 1 – – Observation of  family R =  (e + e -  hadrons) /  0 (e + e -   +  - )  0 = 4  2 / 3s J PC of photon  produced in e + e - collisions

12. 12 Observation of  cJ and  c 1 – – 0 – + (0,1,2) + +  (2S)   cJ   cJ  J/    (2S)   c  E1 M1

13. 13 – DASP, DESY (1976) – Crystall Ball, SLAC (1980) Observation of Crystal Ball: sphere with 900 NaI crystals  cJ  c

14. 14 Charmonium before B-factories 1980 – 2002 : no new charmonium states

15. 15 Bottomonium before B-factories  (1S),  (2S) – 1977 FNAL pA collisions e+e- colliders: DORIS, DORIS-II (DESY) CESR (Cornell) VEPP-4 (Novosibirsk) 1985 – 2008 : no new bottomonium states Lederman 1 – – (0,1,2) + +

16. 16 B-factories @ KEK @ SLAC Data taking : 2000 – 2010 e + e – →  (4S) E cms ~ 10.6 GeV

17. 17 Charmonium production at B factories in B decays initial state radiation J PC = 1 – – double charmonium production γγ fusion J PC = 0 ± +, 2 ± + Only J PC = 0 ± + observed so far. Any quantum numbers can be produced, to be determined from angular analysis.  c (2S)  c2 (2P)

18. 18 Observation of h c (1P) 1 – –  (2S)  h c (1P)  0 1 + – CLEOc 2005 (c-Factory) 00

19. 19 QCD potential one-gluon exchange, asymptotic freedom confining potential, “chromoelectric tube” There are other parameterizations, shapes are similar for 0.1 < R < 1 fm. Schrödinger equation cc J/  c2  (2S)

20. 20 State Experim Predictions of Potential Models

21. 21 Predictions of Potential Models J PC M, GeV Potential models reproduce also annihilation widths J/, (2S) → ℓ + ℓ -  c  cJ  →  and radiative transitions btw. charmonia.

22. 22 X(3872)

23. 23 PRL91,262001 (2003) X(3872) was observed by Belle in B + → K + X(3872)  2S  → J/ψ π + π - Recent signals of X(3872) → J/ψ π + π - X(3872) Confirmed by CDF, D0 and BaBar (+LHCb) pp collisions PRL93,162002(2004) arXiv:0809.1224 PRD 77,111101 (2008) PRL103,152001(2009) direct production only 16% from B

24. 24 Puzzles of X(3872)  M  = 3871.63  0.19 MeV, Γ < 1.2 MeV (90% C.L.) Bf(X  J/   ) / Bf(X  J/   ) = 0.21  0.06 M(  +  - )   +  - pair is produced via  0 X(3872) is observed in isospin-violating mode Mass above DD threshold, but very narrow 2003 revolution Bf(X  J/   ) / Bf(X  J/   ) = 0.8  0.3 confirm even C-parity Mass close to D* 0 D 0 threshold:  m = – 0.09  0.34 MeV expect for cc ~20 _ Very unlikely that X(3872) is charmonium _ X(3872) → J/ψ π + π -

25. 25 Exotic interpretations tetraquarkmolecule compact diquark- diantiquark state two loosely bound D mesons Tetraquark  Maiani, Polosa, Riquer, Piccini; Ebert, Faustov, Galkin; … 1.Charged partners of X(3872). 2.Two neutral states ∆M = 8  3 MeV, one populate B + decay, the other B 0. Predictions: BaBar, Belle : J/  +  0 channel  no charged partner CDF : signal shape in J/  +  - channel Belle : production in B + and B 0 decays no 2 nd neutral resonances Experiment: Tetraquarks are not supported by any experimental evidence.

26. 26 Molecule a few fm Mass close to D* 0 D 0 threshold:  m = – 0.09  0.34 MeV Swanson, Close, Page; Voloshin; Kalashnikova, Nefediev; Braaten; Simonov, Danilkin... Weakly bound S-wave D* 0 D 0 system _ Large isospin violation  8 MeV difference btw D* + D - and D* 0 D 0 thresholds. Large production rate in pp and in B decays  admixture of  c1 (2P). _ J P = 1 + Bound state J/  +  - D0D00D0D00 D* 0 D 0 Virtual state J/  +  - D0D00D0D00 Predicts different line shapes for J/  +  - and D* 0 D 0 modes: _

27. 27 B + & B 0  D 0 D *0 K 4.9σ 347fb -1 PRD77,011102(2008) B  K D 0 D *0 605 fb -1 D*→DγD*→Dγ D*→D0π0D*→D0π0 Flatte vs BW similar result: 8.8σ arXiv:0810.0358 X(3872) → D* 0 D 0 ~2  Shifted mass and higher width are in accord with molecular model Bf(X  DD*) / Bf(X  J/  ) = 9.5  3.1

28. 28 Molecule (2) Kalashnikova, Nefediev arXiv:0907.4901 Simultaneous analysis of J/  and DD* data Bound or virtual?  c1 (2P) admixture? ~2  experimental difference reverses conclusion  Present statistics are insufficient to constrain theory State  c1 (2P) admixture Belle databound~ 30% BaBar datavirtual~ 0  Braaten, Stapleton Zhang, Meng, Zheng arXiv: 0907.3167 0901.1553

29. 29 Angular analysis CDF, BELLE  all J PC except 1 ++ and 2 -+ are excluded cos  X cos  cos  l cos   cos  X cos  cos  l cos   MC J PC =1 ++ MC J PC = 2 -+

30. 30 Nature of binding force One pion exchange ? Coupled channel resonance ? D D D*  c1

31. 31 “Loose ends” Angular analysis to discriminate J PC =1 ++ and 2 – + Improve line-shape measurement for D* 0 D 0 Super B-factories More decay channels :  0  0 ,  +  -  c LHCb BELLE ?, LHCb, Super B-factories _

32. 32 1 – – family

33. 33 Use ISR to measure open&hidden charm exclusive final states ISR at B factories Quantum numbers of final states are fixed J PC = 1 – – Continuous ISR spectrum: access to the whole √s interval α em suppression compensated by huge luminosity comparable sensitivity to energy scan (CLEO-c, BES) e–e–e–e– e+e+e+e+ e+e+e+e+ e–e–e–e– c γ s =(E cm – E γ ) 2 – p 2 c e–e–e–e– e+e+e+e+

34. 34 e + e – →  ISR J/  (  )  +  - : Y(4008,4260,4360,4660) Above DD threshold, decay to open charm? – PRL99, 182004 550/fb PRL99, 142002 670/fb arXiv: 0808.1543 454/fb PRL98, 212001 298/fb

35. 35 No evidence for Y’s → hadrons y (3770) Durham Data Base Y( 4008) y (4040) y (4160) Y( 4260) Y( 4325) y (4415) Y (4660) ψ (3770) Y( 4008) ψ (4040) ψ(4160) Y( 4260) Y( 4360) ψ (4415) Y (4660) R(s) = – R uds  (e + e – →hadrons)  (e + e – →μ + μ – )   ee is small. Since  ee B(Y  ) is finite (is measured)  B(Y  ) is big X.H. Mo et al, PL B640, 182 (2006)  (  → J/  +  - ) = 0.104 ± 0.004 MeV  (  → J/  +  - ) = 0.044 ± 0.008 MeV Much larger than measured charmonium widths:   (Y(4260) → J/  +  - ) > 0.508 MeV @ 90% CL

36. 36 Interpretation – PRD80, 091101R (2010) hybrid → D** D 1 – → (D*π) D DD*  Y(4260) ψ(4415) hybrid state with excited qluonic degree of freedom c c – π π hadrocharmonium charmonium embedded into light hadron predictions?

37. 37 DDDD * D*D*D*D* DDπ DD * π Λ + c Λ – c D ( * )+ s D ( * )– s Inclusive cross-section is saturated by exclusive contributions

38. 38 Charged resonances with bb _  (5S)   Z b (10610) +  - Z b (10650) +  -  (1S)  +  -  (2S)  +  -  (3S)  +  - h b (1P)  +  - h b (2P)  +  - arXiv:1103.3419arXiv:1110.2251

39. 39 Integrated Luminosity at B-factories > 1 ab -1 On resonance:  (5S): 121 fb -1  (4S): 711 fb -1  (3S): 3 fb -1  (2S): 24 fb -1  (1S): 6 fb -1 Off reson./scan : ~100 fb-1 530 fb -1 On resonance:  (4S): 433 fb -1  (3S): 30 fb -1  (2S): 14 fb -1 Off reson./scan : ~54 fb-1 (fb -1 ) asymmetric e+e- collisions

40. 40  ( 5S ) Belle took data at E=10867  1 MэВ 2M(B s ) BaBar PRL 102, 012001 (2009)  ( 6S )  ( 4S ) e + e - hadronic cross-section study  ( 1S )  ( 2S )  ( 3S )  ( 4S ) 2M(B) e + e - ->  (4S) -> BB, where B is B + or B 0 e + e - -> bb (  (5S)) -> B ( * ) B ( * ), B ( * ) B ( * ) , BB , B s ( * ) B s ( * ),  (1S) ,  X … _ _____

41. 41 Puzzles of  (5S) decays 41 PRL100,112001(2008)  (MeV) 10 2 PRD82,091106R(2010) Anomalous production of  (nS)  +  - Similar effect in charmonium?  shapes of R b and  (  ) different (2  ) to distinguish  energy scan  (5S) line shape of Y b Y(4260) with anomalous  (J/   +  - )  assume  Y b close to  (5S)

42. 42 h b (1P) & h b (2P) Observation of

43. 43 Trigger Y(4260)  Y b  search for h b (nP)  +  - @  (5S) CLEO observed e + e - → h c  +  – @ E CM =4170MeV PRL107, 041803 (2011)  (h c  +  – )   (J/   +  – ) 4260 Hint of rise in  (h c  +  - ) @ Y(4260) ? Y(4260)

44. 44 MM(  +  - ) Introduction to h b (nP) (bb) : S=0 L=1 J PC =1 +   M HF  test of hyperfine interaction For h c  M HF = 0.00  0.15 MeV, expect smaller deviation for h b (nP) _ Expected mass  (M  b0 + 3 M  b1 + 5 M  b2 ) / 9  (3S) →  0 h b (1P) BaBar 3.0  arXiv:1102.4565 PRD 84, 091101 Previous search

45. 45 MM(  +  - ) Introduction to h b (nP) (bb) : S=0 L=1 J PC =1 +   M HF  test of hyperfine interaction For h c  M HF = 0.00  0.15 MeV, expect smaller deviation for h b (nP) _ Expected mass  (M  b0 + 3 M  b1 + 5 M  b2 ) / 9  (3S) →  0 h b (1P) BaBar 3.0  arXiv:1102.4565 PRD 84, 091101 Previous search

46. 46  (5S)  h b  +  - reconstruction h b → ggg,  b (→ gg)  no good exclusive final states reconstructed “Missing mass” M(h b ) =  (E c.m. – E  +  - ) 2 – p  +  - ** 2  M miss (  +  - )  (1S)  (2S)  (3S) h b (2P)h b (1P)

47. 47 Results 121.4 fb -1 h b (1P) 5.5  h b (2P) 11.2  Significance w/ systematics

48. 48 Hyperfine splitting h b (1P) (1.7  1.5) MeV/c 2 h b (2P) (0.5 +1.6 ) MeV/c 2 -1.2 Deviations from CoG (Center of Gravity) of  bJ masses consistent with zero, as expected Ratio of production rates  Mechanism of  (5S)  h b (nP)  +  - decay violates Heavy Quark Spin Symmetry for h b (1P) for h b (2P) no spin-flip = spin-flip Process with spin-flip of heavy quark is not suppressed

49. 49 Resonant structure of  (5S)  h b (nP)  +  -

50. 50 Resonant structure of  (5S)  h b (1P)  +  - M(h b  – ), GeV/c 2 phase-space MC M(h b  + ), GeV/c 2

51. 51 Resonant structure of  (5S)  h b (1P)  +  - Results MeV  2 = non-res.~0 Fit function ~BB* threshold _ ~B*B* threshold __  1 = MeV MeV/c 2 M 2 = M 1 =MeV/c 2 a =  = degrees Significance (16  w/ syst)18  121.4 fb -1 M(h b  – ), GeV/c 2 phase-space MC M(h b  + ), GeV/c 2 fit M miss (  +  – ) in M(h b  ) bins  M(h b  ), GeV/c 2 h b (1P) yield / 10MeV  Z b (10610), Z b (10650)

52. 52 Resonant structure of  (5S)  h b (2P)  +  - Significances (5.6  w/ syst)6.7  M(h b  – ), GeV/c 2 phase-space MC M(h b  + ), GeV/c 2 fit M miss (  +  – ) in M(h b  ) bins  121.4 fb -1 M(h b  ), GeV/c 2 h b (1P) yield / 10MeV non-res.~0 h b (1P)  +  - h b (2P)  +  - non-res. set to zero degrees MeV/c 2 MeV c o n s i s t e n t MeV  2 =  1 = MeV MeV/c 2 M 2 = M 1 =MeV/c 2 a =  = degrees MeV

53. 53 Resonant structure of  (5S)  (nS)  +  - (n=1,2,3)

54. 54  (5S)   (nS)  +  -  +- +- (n = 1,2,3)  (1S)  (2S)  (3S) reflections M miss (  +  - ), GeV/c 2

55. 55  (1S)  (2S)  (3S)  (5S)   (nS)  +  - (n = 1,2,3) M miss (  +  - ), GeV/c 2 purity 92 – 94%  +- +-

56. 56  (5S)  (nS)  +  - Dalitz plots  (1S)  (2S)  (3S)

57. 57  (5S)  (nS)  +  - Dalitz plots  (1S)  (2S)  (3S)  Signals of Z b (10610) and Z b (10650)

58. 58 Results of Dalitz plots analyses  (1S)  (2S)  (3S)

59. 59 Results of Dalitz plots analyses  (2S)  (3S)  (1S)

60. 60  M 1  = 10607.2  2.0 MeV   1  = 18.4  2.4 MeV  M 2  = 10652.2  1.5 MeV   2  = 11.5  2.2 MeV Summary of Z b parameters Average over 5 channels Angular analysis  J P = 1 + for both Z b

61. 61  M 1  = 10607.2  2.0 MeV   1  = 18.4  2.4 MeV  M 2  = 10652.2  1.5 MeV   2  = 11.5  2.2 MeV Z b (10610) yield ~ Z b (10650) yield in every channel Relative phases: 0 o for  and 180 o for h b  Summary of Z b parameters Average over 5 channels M(h b  ), GeV/c 2 h b (1P) yield / 10MeV  = 180 o  = 0 o

62. 62 Heavy quark structure in Z b Wave func. at large distance – B(*)B* Why h b  is unsuppressed relative to  Relative phase ~0 for  and ~180 0 for h b Production rates of Z b (10610) and Z b (10650) are similar Widths –”– Existence of other similar states Explains Predicts Other Possible Explanations Coupled channel resonances (I.V.Danilkin et al, arXiv:1106.1552) Cusp (D.Bugg Europhys.Lett.96 (2011),arXiv:1105.5492) Tetraquark (M.Karliner, H.Lipkin, arXiv:0802.0649) Bondar et al. PRD84 054010 (arXiv:1105.4473)

63. 63 States that do not fit qq table QWG, arXiv:1010.5827 _

64. 64 QWG, arXiv:1010.5827 Z(4430) + widths 100–200 MeV  difficult to interpret multiquark candidates BZKBZK rescattering? Pakhlov PLB702,139(2011) States that do not fit qq table

65. 65 Conclusions Quark Model provides good description of quarkonium below open flavor threshold  observations at B-factories Above threshold  new regime : light quarks become important  molecules, hadrocharmonium (... ?) BELLE established new type of elementary particles We knew that neucleons can form bound states (deutron, nuclei) Now we know that D and B mesons can form bound states “Meson chemistry”