1. Homeless mesons X3872 Y3940 Y4260 Stephen L. Olsen University of Hawai’i

2. History: ( sub-atomic particles) 1932: proton & neutron..all we need??? 1937: muon “Who ordered that?” 1947: pion predicted in 1935 1950’s: , , , , ,… “Had I foreseen that, I would have gone into botany” – Fermi chadwick Fermi TingPetersJones Rabi Yukawa Joliet-Curie

3. Hadron “zoo” mesons baryons

4. Quarks restore economy ( & rescue future Fermis from Botany?) (& 3 antiquarks) Mesons: qq p: u +2/3 p: u -2/3 +:+: d -1/3 u +2/3 d +1/3 u -2/3 d +1//3 u +2/3 -:-: u -2/3 d +1/3 s +1/3 u +2/3 d -1/3 s -1/3 Gell-Mann 3 quarks Zweig Baryons: qqq

5. Fabulously successful, but… quarks are not seen why only qqq and qq combinations? What about spin-statistics?

6.  s -1/3 three s-quarks in the same quantum state Das ist verboten!!

7. The strong interaction “charge” of each quark comes in 3 different varieties Y. Nambu O. Greenberg s -1/3 the 3 s -1/3 quarks in the  - have different color charges & evade Pauli --

8. QCD: Gauge theory for color charges generalization of QED    + i e A    + i  i G i QED gauge Xform QCD gauge Xform eight 3x3 SU(3) matrices 8 vector fields (gluons) 1 vector field (photon) scalar charge: e isotriplet charge: erebegerebeg QED QCD Yang Mills Nambu Fritzsch & GellMann

9. Attractive configurations  ijk e i e j e k i ≠ j ≠ k  ij e i ejej same as the rules for combining colors to get white : add 3 primary colors or add color+complementary color antiquarks:  anticolor charges Hence the name: Quantum Chromodynamics quarks: e i e j e k  color charges ejej eiei ekek

10. Difference between QED & QCD QED: photons have no charge QCD: gluons carry color charges gluons interact with each other  Coupling strengths distance

11. Test QCD with 3-jet events (& deep inelastic scattering) rate for 3-jet events should decrease with E cm gluon ss

12. “running”  s Why are these people smiling?

13. Probe QCD from other directions Proposed non-qq or non-qqq hadron spectroscopies: 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 uc u c cc u d u s d

14. Pentaquarks “Seen” in many experiments BaBar CDF but not seen in just as many others High interest: 1 st pentaquark paper has ~500 citations Belle BES

15. Experimental situation is messy (some contradictory experiments) SAPHIR (2004) 4.8  M(nK + )(GeV) Counts/4 MeV nKKγp   s CLAS (2005) Same reaction

16. Some groups contradict themselves 5.2  CLAS-D (2003) no  signal CLAS (2005) ???

17. Pentaquark Scoreboard Positive signals Negative results Also: Belle Compass L3 CLAS Yes: 17 No: 18

18. Plenary speaker at LP05 “The  pentaquark is not in good health, but it is still alive.” - Volker D Burkert Jefferson Lab

19. This talk: non-standard mesons with “hidden charm” standard cc mesons are: –best understood theoretically –narrow & non overlapping c + c systems are commonly produced in B meson decays. b c c s V cb cos  C CKM favored W-W- cc uc u c (i.e containing c & c)

20. Thanks to KEKB we have lots of B mesons (>1M BB pairs/day) >1fb -1 /day Design: 10 34

21. Primer on Charmonium

22. Charmonium r mesons formed from c- and c-quarks c-quarks are heavy: m c ~ 1.5 GeV  2m p velocities small: v/c~1/4 non-relativistic QM applies cc

23. QM of cc mesons cc r What is V(r) ?? derive from QCD quantum chromodynamics

24. “Cornell” potential ~0.1 fm G.S.Bali hep-ph/0010032 “confining” large distance component slope~1GeV/fm 1/r “coulombic” short distance component cc r V(r) 2 parameters: slope & intercept

25. Charmonium spectrum

26. 1 -- Charmonium states J/  ’’ D-meson + anti-D meson mass threshold ”” “narrow” (  ~100KeV)  e+e+ e-e- Directly accessible via e + e - annihilation  (e + e -  hadrons) “narrow” (  ~300KeV) “wide” (  ~25 MeV)  ”  DD decay channel is open  DD)  25MeV

27. P-wave states Gamma energy spectrum from  ’   X decays Gaiser et al (Crystal Ball) PRD 34 711 accessible via E1 transitions from  ’ 2 3 S 1 (  ’ )  1 3 P 2 (  c2 ) 17 keV 2 3 S 1 (  ’ )  1 3 P 1 (  c1 ) 24 keV 2 3 S 1 (  ’ )  1 3 P 0 (  c0 ) 24 keV 1 3 P 2 (  c2 )  1 3 S 1 (J/  ) 420 keV 1 3 P 1 (  c1 )  1 3 S 1 (J/  ) 290 keV 1 3 P 0 (  c0 )  1 3 S 1 (J/  ) 120 keV E1 Transition Partial width Calculable from”1 st principles” Good agreement with measurements

28. Hadronic transitions  (  ’      J/  )  70 keV “allowed”  (  ”      J/  )  50 keV “allowed”  (  ’   J/  )  5 keV SU F (3) violating     (  ’    J/  )  0.3 keV isospin violating “reasonable” agreement between measurement & theory c.f. Kuang & Yan PRD 41 155

29. Recent results 1 3 D 1   1 3 P 1 seen by CLEO hep-ex/0509030   (meas) = 75  18 keV  (theor)  59~77 keV 1 1 P 1 found by CLEO hep-ex/0508037 properties as expected 2 3 P 2 found by Belle hep-ex/0507033 properties as expected 2 1 S 0 found by Belle S.K.Choi et al PRL 89 102001 properties as expected

30. The potential model for cc charmonium mesons is robust and reliable

31. The X(3872) ???? Study     J/  produced in B  K     J/  decays

32. The X(3872) B  K     J/  M(  J  )  ’      J/  X(3872)      J/  S.K. Choi et al PRL 91, 262001

33. Its existence is well established seen in 4 experiments X(3872) CDF X(3872) D0 hep-ex/0406022 9.4  11.6 

34. Is it a cc meson? These states are already identified 3872 MeV Could it be one of these?

35. no obvious cc assignment 3872 c”c” M too low and  too small angular dist’n rules out 1   J/  way too small  c   too small;M(     ) wrong  c  & DD) too small  c should dominate SLO hep-ex/0407033 hc’hc’  c1 ’ 22 22 33

36. go back to square 1 Determine J PC quantum numbers of the X(3872) with minimal assumptions

37. J PC possibilities (for J ≤ 2) 0 -- exotic violates parity 0 -+ (  c ” ) 0 ++ DD allowed (  c0 ’ ) 0 +- exotic DD allowed 1 - - DD allowed (  (3S)) 1 -+ exotic DD allowed 1 ++ (  c1 ’ ) 1 +- (h c ’ ) 2- -(2)2- -(2) 2 - + (  c2 ) 2 ++ DD allowed  c2 ’ ) 2 +- exotic DD allowed

38. J PC possibilities 0 -- ruled out; J P =0 +,1 - & 2 + unlikely 0 -- exotic violates parity 0 -+ (  c ” ) 0 ++ DD allowed (  c0 ’ ) 0 +- exotic DD allowed 1 - - DD allowed (  (3S)) 1 -+ exotic DD allowed 1 ++ (  c1 ’ ) 1 +- (h c ’ ) 2- -(2)2- -(2) 2 - + (  c2 ) 2 ++ DD allowed  c2 ’ ) 2 +- exotic DD allowed

39. Strong evidence for C=+1 13.6 ± 4.4 X(3872)   J/  evts (>4  significance) X(3872)   J/  12.4 ± 4.2 evts12.4 ± 4.2 evts virtual  (782)? X(3872)        J/  Bf(X   J/  ) Bf(X   J/  ) =0.14 ± 0.05 Br(X  3  J/  ) Br(X  2  J/  ) = 1.0 ± 0.5 M(       ) M(     ) X(3872)      J/  Fits to  (760)

40. J PC possibilities (C=-1 ruled out) 0 -- exotic Violates parity 0 -+ (  c ” ) 0 ++ DD allowed (  c0 ’ ) 0 +- exotic DD allowed 1 - - DD allowed (  (3S)) 1 -+ exotic DD allowed 1 ++ (  c1 ’ ) 1 +- (h c ’ ) 2 - - (  2 ) 2 - + (  c2 ) 2 ++ DD allowed  c2 ’ ) 2 +- exotic DD allowed

41. Angular Correlations K  J/         e  e   J=0 X 3872 J z =0 z Rosner (PRD 70 094023) Bugg (PRD 71 016006) Suzuki, Pakvasa (PLB 579 67)

42. ll |cos  l  |  2 /dof = 34/9  |cos  | |cos  |  2 /dof=34/9 0 ++ 0 -+ rule out 0 ++ & 0 -+     J  k    x  J  

43. J PC possibilities (0 -+ & 0 ++ ruled out) 0 -- exotic violates parity 0 -+ (  c ” ) 0 ++ DD allowed (  c0 ’ ) 0 +- exotic DD allowed 1 - - DD allowed (  (3S)) 1 -+ exotic DD allowed 1 ++ (  c1 ’ ) 1 +- (h c ’ ) 2 - - (  2 ) 2 - + (  c2 ) 2 ++ DD allowed  c2 ’ ) 2 +- exotic DD allowed

44. Fits to the M(  ) Distribution X   J/  in P-wave has a q* 3 centrifugal barrier X J/   q*

45. M(  ) can distinguish  -J/  S- & P-waves S-wave:  2 / dof = 43/39 P-wave:  2 / dof = 71/39 q* roll-off q* 3 roll-off (CL=0.1%) (CL= 28%) Shape of M(  ) distribution near the kinematic limit favors S-wave

46. Possible J PC values (J -+ ruled out) 0 -- exotic violates parity 0 -+ (  c ” ) 0 ++ DD allowed (  c0 ’ ) 0 +- exotic DD allowed 1 - - DD allowed (  (3S)) 1 -+ exotic DD allowed 1 ++ (  c1 ’ ) 1 +- (h c ’ ) 2 - - (  2 ) 2 - + (  c2 ) 2 ++ DD allowed  c2 ’ ) 2 +- exotic DD allowed

47. X(3872)  D 0 D 0  0 ? 11.3±3.6 sig.evts (>4  ) Bf(B  KX)Bf(X  DD  )=2.2 ± 0.7 ± 0.4x10 -4 D *0  D 0  0 ? M(D 0 D 0  0 ) 1 ++ : DD* in an S-wave  q* 2 ++ : DD  in a D-wave  q* 5 Strong threshold suppression

48. Possible J PC values (2 ++ ruled out) 0 -- exotic violates parity 0 -+ (  c ” ) 0 ++ DD allowed (  c0 ’ ) 0 +- exotic DD allowed 1 - - DD allowed (  (3S)) 1 -+ exotic DD allowed 1 ++ (  c1 ’ ) 1 +- (h c ’ ) 2 - - (  2 ) 2 - + (  c2 ) 2 ++ DD allowed  c2 ’ ) 2 +- exotic DD allowed 1 ++

49. can it be a 1 ++ cc state? 1 ++   c1 ’ (the only possibility) 3872  Bf(X      J/  )>4% is very large for an isospin-violating channel (Isospin violating) M=3872 MeV is too low, especially now that we know that M(  c2 ’ )=3931  4 MeV

50. Expectations for  ’ c1  (  ’ c1   J/  )  11 keV Barnes Godfrey PRD 69 054008  (  ’ c1      J/  ) = ?  (  ’    J/  )  0.3 keV (“educated” guess?) Bf(X   J/  ) Bf(X   J/  )  30 ~ 40 Bf(X   J/  ) Bf(X   J/  ) =0.14 ± 0.05 Expect: Meas: >200x discrepancy  c1 ’ component of X(3872) is  few% (at most?) can our “education” really be this bad?

51. Intriguing fact M X3872 =3872 ± 0.6 ± 0.5 MeV m D0 + m D0* = 3871.2 ± 1.0 MeV lowest mass charmed meson lowest mass spin=1 charmed meson DD* 2 loosely bound qq color singlets with M = m D + m D* -   u c u c one  exchange attractive for 1 ++ Tornqvist PLB 590, 209 (2004) Deuson? deuteron-like DD* bound state?

52. X(3872) = D 0 D* 0 bound state? J PC = 1 ++ is favored M ≈ m D0 + m D0* Large isospin violation is natural ( & was predicted) :  |D 0 D* 0 > = 1/  2 (|10> - |00>)  (X   J/  ) <  (X   J/  ) was predicted  (X  D 0 D 0  0 ) too large? Bf(B 0  K 0 X 3872 )/Bf(B +  K + X 3872 ) too large? Equal mixture of I=1 & I =0 Swanson PLB 598, 197 (2004) Tornqvist PLB 590, 209 (2004) Swanson PLB 588, 189 (2004) Braaten & Kusunoki PR D71, 074005 predict: < 0.08 BaBar measurement (hep-ex/0507090): 0.5  0.3

53. diquark-antidiquark? Maiani et al predict:  M = M(X u ) – M(X d ) = 8  3 MeV BaBar (hep-ex/0507090) reports:  M = 2.7  1.3  0.2 MeV uc u c dc d c Maiani etal predict a doublet of states PRD 71,014028 (2005) Xu=Xu= Xd=Xd= B+K+XuB+K+Xu B0K0XdB0K0Xd BaBar

54. Are there others? Is the X(3872) a one-of-a-kind curiousity? or the 1 st entry in a new spectroscopy? Look at other B decays  hadrons+J/  B  K  J/  B  K  J/  B  K  J/ 

55. B  K  J/  in Belle “Y(3940)” M≈3940 ± 11 MeV  ≈ 92 ± 24 MeV M bc S.K. Choi & S.L.Olsen et al. (Belle), PRL94, 182002 (2005) M(  J/  ) MeV

56. Y(3940): What is it? Charmonium? –Conventional wisdom: (SU(3)-violating)  J/  decay  should not be a discovery mode for a cc state with mass above DD & DD* threshold! eg.Brambilla et al (QWG) hep-ph/0412158 cc-gluon hybrid? –predicted by QCD, –decays to DD and DD* are suppressed (“open-charm” thresh = m D + m D** = 4.3 GeV) –large hadron+J/  widths can occur –masses expected to be 4.3 ~ 4.4 GeV (higher than what we see) Horn & Mandula PRD 17 898 others

57. J/  sideband Well above DD & DD* threshold but wide & found in a suppressed mode?? M=4259  8 MeV  = 88  23 MeV B. Aubert et al. (BaBar) hep-ph/0506081 Y(4260) 10.58 GeV 4.26 GeV not seen in  (e + e -  hadrons) at Ecm =4.26 GeV J.Z. Bai et al. (BESII) PRL 88 101802 BES BaBar’s Y(4260)  (e + e -  hadrons)

58. summary X(3872): –Existence well established –J PC = 1 ++ –Br(X      J/  ) too high for charmonium –Br(X  D 0 D 0  0 ) too high for molecule –Br(B 0  K S X 3872 ) also too high for molecule(?) –  M too small for diquarks? –Mass too low for hybrid by a factor of more than 200! still under study The more we learn more about it the more puzzling it becomes. (M(X u ) (from B +  K + X u ) - M(X d ) (from B 0  K S X d )

59. other odd-balls Y(3940) Belle –  ( Y 3940   J/  too high for charmonium –Mass too low for a hybrid Y(4260) BaBar –  (y 4260      J/  also way too high –1 --, but not seen in e + e -  hadrons by factors of ~10 3

60. 3872 Charmonium chalet Isospin violators not welcome Fussy! Y3940 Y4260 Looking for a home:

61. 3872 rats! Molecule Manors DD  Y3940 Y4260

62. 3872 Hydrid heaven M<4.2 GeV need not apply Fat Cats! Y3940 Y4260

63. 3872 Diquark dives *#!?&%$! Doublets only no singlets! Y3940Y4260

64. Conclusion either: –The “standard model” for charmonium mesons needs major revision or: –There is a new hadron spectroscopy in the 3.5~4.5 GeV mass region Opportunities for CLEO-c & BES-III ???

65. Back-up slides

66. X u – X d Mass difference?: M Xu – M  ’ = 185.7  0.6 MeV M Xd – M  ’ = 184.0  1.3 MeV M(X u ) – M(X d ) = 0.8  1.4 MeV Belle: Preliminary

67. Another one? e + e -  J/  + X >4  )peak at M=3940  11 MeV N=148  33 evts Width consistent w/ resolution (= 32 MeV) cc cc  c0 cc ‘ ‘ What is it?  c0 ?  c ?? ‘“

68. Look at e + e -  J/  D(D ( * ) ) Reconstruct a J/  & a D use D 0  K -  + & D +  K -  +  + Determine recoil mass

69. Look at M(DD ( * ) ) DD* DD 3940 MeV 9.9 ± 3.3 evts (4.5  ) 4.1 ± 2.2 evts (2.1  )  c0  DD* ‘  c  DD “

70. Other hadronium states? M=1859 MeV/c 2  < 30 MeV/c 2 (90% CL) J/    pp in the BES expt M(pp)-2m p (GeV) 00.10.20.3 acceptance  2 /dof=56/56 fitted peak location +3 +5  10  25 J.Z.Bai PRL 91,022001(2003)