1. Evidence for Exotic Mesons Belle Workshop on light flavors & chiral dynamics 北 大 Sept 29-30,2007 Stephen Olsen U. of Hawai’i & 高能所 北京 BaBar

2. X(3872) Y(4260) X(3940) Y(3940) Y(4325) Y(4660) X(4160) Y(4008) Y(4780) Z(4430) Talk outline

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

4. Fabulously successful mesons q q

5. QCD suggests non-qq meson spectroscopies Glueballs: gluon-gluon color singlet states Multi-quark mesons: molecules: diquark-antidiquark: qq-gluon hybrid mesons d c d c cc d c dc

6. Searching for non-QPM hadrons is a risky business

7. Remember the pentaquark T.Nakano et al (LEPS) PRL 91 012002 (2003)  742 citations  + (1530)? forget

8. You never can be sure: or something else. Is mother nature is smiling at you?

9. The XYZ mesons: candidates for non-qq states cc uc u c 4 quark candidates (from Belle) “hybrid” qq-gluon candidates (from Babar & Belle)

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

11. 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

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

13. Lots new on the “XYZ” particles X(3872) –     J/  in B  K     J/  Z(3930) –DD in   DD Y(3940) –  J/  in B  K  J/  X(3940) – e + e -  J/  X & e + e -  J/  DD* Y(4260) –     J/  in e + e -      J/  Y(4325) –  +  -  ’ in e + e -   +  -  ’ Y(4008)? Y(4250) Y(4370) Y(4660) X(3880)  DD - e + e -  J/  DD X(4160)  D*D* - e + e -  J/  D*D* Z + (4430)   +  - B  K  +  ’ New Belle/BaBar results: (Summer 2007) Status spring 2007: confirmed by BaBar updated by Belle

14. I’ll concentrate on recent results.

15. X(3872) >300 citations

16. X(3872) properties (PDG2007) M D0 + M D*0 = 3.871.8 ± 0.4 MeV

17. M(  ) looks like     2 / dof = 43/39 (CL=28%) kinematic limit≈m  PRL 96 102002 CDF Belle Belle & CDF: J PC = 1 ++  most likely

18. What’s new with the X(3872)? BaBar confirms Belle’s DD  threshold enhancement Mass is 3.8 ± 1.2 MeV above WAvg X(3872)   J/  mass; (~3  is this significant? Both groups see a high mass value

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

20. Is there a cc slot for the X(3872)? 3872   r  J/  too small   r (  J/  ) too big 1 ++  (  c1 ’)   c    J/  ispin forbidden  D 0 D 0  0 @ thresh.suppressed  B  Kcc(J=2) suppressed 2 -+ (  c2 )

21. Y(3940) in B  K  J/  M≈3940 ± 11 MeV  ≈ 92 ± 24 MeV Belle PRL94, 182002 (2005) M(  J/  ) MeV M 2 (K  ) GeV 2 M 2 (  J  ) GeV 2

22. Y(3940) properties Belle PRL94, 182002 (2005) M(  J/  ) MeV  (Y 3940   J/  > 7 MeV (an SU F (3) violating decay) ~ this is 10 3 x  (  ’   J/  (another SU F (3) violating decay) if the Z(3930) is the  c2 ’ the Y(3940) mass is too high for it to be the  c1 ’

23. Confirmed by BaBar this summer B ±  K ±  J/  B 0  K S  J/  M 2 (K  )  J  ) ratio Some discrepancy in M &  ; general features agree G.Cibinetto EPS-2007

24. Is there a cc slot for Y(3940) ? Can M(  c1 ’)>M(  c2 ’)?  c1 ’ Mass is low c”c” “ “  c0 ’ 3940 3931 For any charmonium assignment,  [Y(3940)   J/  is too large.

25. Belle updates e + e -  J/  D ( * ) D ( * ) D(*)D(*) Use “partial reconstruction technique” reconstruct these J/  D(*)D(*) “Recoil” D ( * ) undetected (inferred from kinematics) Continuum e + e - annihilation e+e+ e-e-

26. J/  D ( * ) recoil mass J/  DD J/  DD* J/  D*D* J/  DD* Partial reconstruction reconstruct Belle arXiv:0708.3812

27. M(DD*): Confirm X(3940)  DD* D-reconstructed D * -tag D sidebands 6.0  Bg subtracted M = 3942 +7 ± 6 MeV  tot = 37 +26 ±12 MeV Nsig =52 +24 ± 11evts -6 -15 -16 Previous values: M = (3943 ± 6 ± 6) MeV  = (15.4  10.1) MeV  < 52 MeV at 90%CL PRL 98, 802001 (2007) arXiv:0708.3812

28. Is there a cc slot for X(3940) ? Mass is > M(  c2 ’) & no  c1 recoil seen  c1 ’ Mass is ~ 60 MeV low (if  (3S) =  (4040)) c”c”  c0 ’ 3940 3931 Mass is > M(  c2 ’) & DD decays not seen Maybe the  c ”

29. M(DD): Broad threshold enhancement arXiv:0708.3812 Relativistic BW D sidebands D-reconstructed D-tag 3.8  Bg subtracted Resonance? Thresh effect? … ?

30. M(D*D*)  a new state at ~4160 MeV D*-reconstructed + D*- tag 5.5  M = 4156 +25 ± 15 MeV  tot = 139 +111 ± 21MeV Nsig =24 +12 ± 11evts -20 -61 -8 arXiv:0708.3812 It has to have C=+; most likely 0 -+,... possibly 0 ++ if 0 ++, why is it not seen in DD

31. A cc assignment for X(4160) ? Mass is far too low (unless  (4S)=  (4160), but, then, where is  (2D?))  c ’’’ Mass is too high (if  (3S)=  (4040)) or too low (if  (3S) =  (4160)) c”c” 3940 3931 Can place either the X(3940) or X(4160), but probably not both.

32. The 1 -- states seen in ISR

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

34. Not seen in e + e -  hadrons  (Y4260      J/  ) > 1.6MeV @ 90% CL X.H. Mo et al, PL B640, 182 (2006) 4260 BES data ~3nb  peak  Y(4260)  +   J/  pb Huge by charmonium standards

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

36. M(  ) near 4008 & 4260 MeV 3.8 < M(  J/  ) <4.2 GeV 4.2 < M(  J/  ) <4.4 GeV

37. No 1 -- cc slot for the Y(4260) 4280 4260 X.H. Mo et al, hep-ex/0603024

38. Is the Y(4260) a cc-gluon hybrid? cc 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)  (  J/  ) larger than that for normal charmonium  (e + e - ) smaller than that for ordinary charmonium Horn & Mandula PRD 17, 898 (1977) 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) Y(4260) seems to match all of these !!!

39. DD** thresholds in & “Y(4260)” 4.28-m D D** spectrum M(     J/  ) GeV No obvious distortions D1DD1D D2DD2D

40. BaBar      ’ peak at 4325MeV Nbkg = 3.1  1.0 Nevt = 68 (<5.7 GeV/c 2 )  2 -prob < 5.7 GeV/c 2 Y(4260) 6.5  10 -3  (4415)1.2  10 -13 Y(4320)29% e + e -   ISR      ’ M=4324  24 MeV  = 172  33 MeV above all D**D thresholds S.W.Ye QWG-2006 June 2006 Not Compatible with the Y(4260) D1DD1D D2DD2D 298 fb -1 (BaBar) hep-ex/0610057 BaBar PRL 98 252001 (2007)

41. 4325 MeV      ’ peak in Belle (new) M=4324  24 MeV  = 172  33 MeV 548 fb -1 X.L. Wang et al (Belle) arXiv:0707.3699 Two peaks! M=4664  11 ± 5 MeV  = 48  15 ± 3 MeV M=4361  9 ± 9 MeV  = 74  15 ± 10 MeV BaBar values (both relatively narrow) (& both above D**D thresh) (& neither consistent with 4260) 4260

42. Y(4660)  f 0 (980)  ’? 4.0 < M(  ’ ) <4.5 GeV4.5 < M(  ’ ) <4.9 GeV f 0 (980)?

43. K + K - J/  from Belle (very new) C.Z.Yuan et al (Belle) arXiv:0709.2565  (4415)? M=4875  132 MeV  = 630  126 MeV M=4430 +38 MeV  = 254 +55 MeV 4260 -43 -46

44. M(K + K - )

45. Latest News electrically charged!!

46. M(  ±  ’) from B  K  ±  ’ M 2 (K  ) GeV 2 M 2 (  ’ ) GeV 2 K. Abe et al (Belle) arXiv:0708.1790 K*  K  K 2 *  K  Veto M(  ’ ) GeV 6.5  M = 4433 ± 4 ±1 MeV  tot = 45 +17 +30 MeV Nsig =124 ± 31evts -13-11

47. Could this be a reflection from the K  channel?

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

49. Can interference between K  partial waves produce a peak? Only S-, P- and D-waves seen in data interfere Add incoherently

50. Can we make a peak at cos   ≈0.25 with only S-, P- & D-waves? Not without introducing other, even more dramatic features at other cos   (&, , other M  ’ ) values.

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

52. 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)   ’ & Z + (4430)     ’ have large Q but  ≈50 MeV characterized by large partial widths (Bfs) to hadrons+J/  (or  ’)  – Br(X(3872)   J/  ) > 4.3% (Isospin=1) –  (Y(3940)   J/  ) > 7 MeV (SU(3) octet) –  (Y(4260)      J/  ) > 1.6 MeV States that decay to  ’ not seen decaying to J/  (and vice-versa) –Bf(Y(4660)   ’) >> Bf(y(4660)   J/  )  same for Y(4360) & Z(4430   ’ –Y(4260) not seen in Y(4260)   ’ 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 (mine)

53. New 1 -- states     J/      J/   ’ ’

54. some of the states are near thresholds, but this is not a universal feature D S D S thresholdsDD thresholds

55. D*D* DD* DD  tot Y(4660)Y(4360) Y(4260) Y(4008) The 1 -- states do not match well to peaks in hadr. cross-sections Pakhlova (Belle) PRL 98, 092001 (2007)

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

57. 謝謝

58. Inclusive B  Kx from BaBar ? Fully reconstructed B - tags

59. M 2 (  ’ ) / cos   plot 1.0< M(K  )<1.4 GeV Our attempts to fit the M=4.43 GeV (cos   =0.25) peak with any combination of S-, P- & D-waves

60. BaBar looked for a charged partner of the X(3872) and excluded isospin 1: BF(B 0  X - K + ) BF(X  J/ψ  -  0 ) < 5.4 x 10 -6 BF(B -  X - K 0 ) BF(X  J/ψ  -  0 ) < 2.2 x 10 -5 c.f BF(B 0  X 0 K+ ) BF(X 0  J/ψ  --  + ) =(1.28  0.41 ) x 10 -5