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Nonstandard mesons

Nonstandard mesons. Stephen L. Olsen University of Hawai’i. tetra-quarks meson-meson molecules q q – q q diquark pairs q q-gluon hybrids nucleon-antinucleon baryonium. u. c. u. c. u. c. u. c. c. c. d. u. u. u. d. u. This talk.

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Nonstandard mesons

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  1. Nonstandard mesons Stephen L. Olsen University of Hawai’i • tetra-quarks • meson-meson molecules • q q – q q diquark pairs • q q-gluon hybrids • nucleon-antinucleon baryonium u c u c u c u c c c d u u u d u

  2. This talk • Candidate non-standard mesons with hidden charm from Belle & BaBar • Candidate baryonium meson from BES c c u c u c probably no time for: d u u u d u

  3. Concentrate on “hidden charm” systems (i.e containing c & c) u c c c u c • standard cc mesons are: • best understood theoretically • narrow & non overlapping • cc systems are prolifically produced in B meson decays. c c Vcb b W- cosqC s CKM favored

  4. Thanks to KEKB, Belle has lots of B mesons(>1M BB pairs/day) >1fb -1/day Design: 10 34

  5. Charmonium primer These states have not yet been found Hadronic transitions DD(*) decays dominate G~wide (10’s of MeV) G(y’p+p-J/y) 70 keV G(y”p+p-J/y) 50 keV G(y’hJ/y)  5 keV SUF(3) violating G(y’p0J/y)  0.3 keV isospin violating These states have all been identified p0 h p+p- p+p- EM transitions G(E1)  100~300 keV Below DD(*) thresholds G~narrow (~<MeV ) G(allowed M1)  1 keV

  6. X(3872)p+p-J/y BK p+p-J/y y’p+p-J/y X(3872)p+p-J/y M(ppJ/y) –M(J/y) S.-K.Choi, S.L.Olsen et al (Belle) PRL 91 262001 (2003)

  7. The X(3872) is well establishedseen in 4 experiments CDF 9.4s 11.6s X(3872) D0 BaBar X(3872) hep-ex/0406022

  8. Is it a cc meson? If so, it must be one of these? 3872 MeV

  9. no obvious cc assignment hc” hc’ cc1’ y2 hc2 y3 M too low and G too small angular dist’n rules out 1+- 3872 G(gJ/y) way too small G(gcc1) too small;M(p+p-) wrong pp hc should dominate G( gcc2 & DD) too small SLO hep-ex/0407033

  10. go back to square 1 Determine JPC quantum numbers of the X(3872) with minimal assumptions

  11. JPC possibilities (for J ≤ 2)

  12. JPC possibilities0-- ruled out; JP=0+,1- & 2+ unlikely

  13. Strong evidence for C=+1 X(3872)gJ/y X(3872)p+p-p0J/y 12.4 ± 4.2 evts virtual w(782)? M(p+p-p0) Br(X3pJ/y) Br(X2pJ/y) = 1.0 ± 0.5 13.6 ± 4.4 X(3872)gJ/y evts (>4s significance) X(3872)p+p-J/y Bf(XgJ/y) Bf(XppJ/y) =0.14 ± 0.05 Fits to r(760) M(p+p-)

  14. JPC possibilities (C=-1 ruled out)

  15. Angular Correlations r Jz=0 J=0 X3872 J=0 K z Rosner (PRD 70 094023) Bugg (PRD 71 016006) Suzuki, Pakvasa (PLB 579 67) J/y

  16. ereJ/y k(erxeJ/y) 0++ 0-+ q qlp y c2/dof=18/9 c2/dof = 34/9 |cosq| c2/dof=34/9 |cosqlp| rule out 0++ & 0 -+ |cosy|

  17. JPC possibilities (0-+ & 0++ ruled out)

  18. M(pp) can distinguish r-J/y S- & P-waves P-wave: c2/dof = 71/39 S-wave: c2/dof = 43/39 (CL=0.1%) (CL= 28%) q* roll-off q*3 roll-off Shape of M(pp) distribution near the kinematic limit favors S-wave

  19. Possible JPC values (J-+ ruled out)

  20. X(3872)D0D0p0 ? D*0D0p0? • 1++ : DD* in an S-wave  q* • 2++ : DDp in a D-wave  q*5 Strong threshold suppression M(D0D0p0) 11.3±3.6 sig.evts (>4s) Bf(BKX)Bf(XDDp)=2.2±0.7±0.4x10-4

  21. Possible JPC values (2++ ruled out) 1++

  22. can it be a 1++ cc state? 1++cc1’ (the only possibility) Bf(Xp+p- J/y)>4% is very large for an isospin-violating channel 3872 p+p- (Isospin violating)

  23. Expectations forc’c1 G(c’c1 g J/y)  11 keVBarnes Godfrey PRD 69 054008 G(c’c1 p+p- J/y) = ?  G(y’  p0J/y)  0.3 keV(“educated” guess?) Bf(XgJ/y) Bf(XppJ/y)  30 ~ 40 Expect: >200x discrepancy Bf(XgJ/y) Bf(XppJ/y) can our “education” really be this bad? Measmnt: =0.14 ± 0.05 cc1’ component of X(3872) is few% (at most?)

  24. Intriguing fact lowest mass charmed meson lowest mass spin=1 charmed meson MX3872 =3872 ± 0.6 ± 0.5 MeV mD0 + m D0* = 3871.2 ± 1.0 MeV Deuson? deuteron-like DD* bound state? 2 loosely bound qq color singlets with M= mD + mD* - d c c D p D* u u one p exchange attractive for 1++ Tornqvist PLB 590, 209 (2004)

  25. X(3872) = D0D*0 bound state? • JPC = 1++ is favored • M ≈ mD0 + mD0* • Large isospin violation is natural (& was predicted):  |D0D*0> = 1/2(|10> - |00>) • G(XgJ/y) < G(XppJ/y) was predicted • G(XD0D0p0) too large? • Bf(B0K0X3872)/Bf(B+K+X3872) too large? Tornqvist PLB 590, 209 (2004) Equal mixture of I=1 & I =0 Swanson PLB 588, 189 (2004) Swanson PLB 598, 197 (2004) Braaten & Kusunoki PR D71, 074005 predict: <0.08 BaBar measurement (hep-ex/0507090): 0.5  0.3

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

  27. Are there others?Is the X(3872) a one-of-a-kind curiousity? or the 1st entry in a new spectroscopy? Look at other B decays  hadrons+J/y: BK h J/y BK p J/y BK w J/y

  28. BK wJ/y in Belle “Y(3940)” M≈3940 ± 11 MeV G≈ 92 ± 24 MeV Mbc Mbc Mbc M(wJ/y) MeV S.K. Choi & S.L.Olsen et al. (Belle), PRL94, 182002 (2005)

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

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

  31. summary by a factor of more than 200! • X(3872): • Existence well established • JPC = 1++ • Br(Xp+p- J/y) too high for charmonium • Br(XD0D0p0) too high for molecule • Br(B0 KSX3872) also too high for molecule(?) • DM too small for diquarks? • Mass too low for hybrid still under study (M(Xu) (from B+K+Xu) - M(Xd) (from B0KSXd) The more we learn more about it the more puzzling it becomes.

  32. summary (cont’d) • Y(3940) Belle • G( Y3940 wJ/y) too high for charmonium • Mass too low for a hybrid • Y(4260) BaBar • G(y4260p+p-J/y) also way too high • 1--, but not seen in e+e- hadrons by factors of ~103

  33. Homeless mesons • X(3872) • Y(3940) • Y(4260) • … Mahalo enjoy mid-autumn festival in Hawaii 但願人長久千里共嬋娟

  34. Back-up slides

  35. Baryonium at BES??? d u u u d u

  36. Phys. Rev. Lett. 91, 022001 (2003) J/y g pp (at BES) acceptance weighted BW M(pp) +3 +5 -10 -25 M=1859 MeV/c2 G < 30 MeV/c2 (90% CL) 0 0.1 0.3 0.2 3-body phase space M(pp)-2mp (GeV)

  37. Baryonium potential & Wave fcn G.J. Dung & M.L. Yan hep-ph/0502127 Potential barrier “Rectangularized” Skyrmion-type potential I = 0, Jpc=0-+ pp annihilation M ~ 1860 MeV G ~ 16 MeV  large uncertainties -V0d(r) X  p+p- h’should be a strong channel

  38. M(p+p-h’) from J/y g p+p-h’ +- mass spectrum for +- &   modes 7.7 M = 183463 MeV G = 68  20 8 MeV BESII Preliminary

  39. _ Re-fit J/pp including FSI M = 1830.6  6.7 MeV  = < 153 MeV @90%C.L. I=0 FSI In good agreement with X(1835) Sirbirtsev et al. (PRD 71 054010 )

  40. Appendix • Other new hidden charm particles from Belle (near 3940!) • X(3940) • Z(3931)

  41. Other new particles from Belle e+e-J/y + X

  42. X(3940)DD* seen(DD & wJ/y not seen)

  43. gg  Z(3931) DD at Belle sin4q (J=2) 4111 evts (5.5) M=3931 4  2 MeV =208 3 MeV

  44. Z(3931) = cc1’(almost for sure) ? X(3940)  Y(3940) (maybe the hc’’)

  45. Jon Coleman Moriond-QCD March 2005 e+e-B+B- K-X0 244 fb-1 • Can measure absolute B.F.’s of B-K-X0 J/y Lower limit on BF(XJ/ypp) > 4.3% @ 90% C.L cc2 cc1 cc0 Very clear J/y and hc signals N J/y=258+- 42 N hc =266 +-42 • cc2,cc0<<cc1 • X(3872) production much lower than for other Charmonium states: • can set lower limit on B.F.

  46. Kinematic variables BK gJ/y Ecm/2 e+ e- B B ϒ(4S) Ecm/2 DE CM energy difference: BK gJ/y Beam-constrained mass: Mbc

  47. 1++ compute angles in X(3872) restframe 1++: sin2ql sin2c c2/dof = 11/9 ql K |cosql| c2/dof = 5/9 c |cosc| 1++ looks okay!

  48. M(gJ/y) look-back plot

  49. Fit cosqlp with 1++ MC c2/dof=11.9/9 |cosqlp|

  50. Y(3940): What is it (cont’d)? • a molecule? • M ≈ 2mDs • not seen in YhJ/y • (h contains ss) • width too large?? • no p exchange for DSDS c s s c ?? PRL 93, 041801 M(h J/y)

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