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New Results on Charmonium and Charmonium(-like) States from Belle

New Results on Charmonium and Charmonium(-like) States from Belle. Jens Sören Lange Justus-Liebig-Universität Gießen hadron2011 XIV International Conference on Hadron Spectroscopy 06/16/2011 Künstlerhaus, München .

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New Results on Charmonium and Charmonium(-like) States from Belle

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  1. New Results onCharmonium and Charmonium(-like) Statesfrom Belle Jens Sören LangeJustus-Liebig-Universität Gießen hadron2011XIV International Conference on Hadron Spectroscopy 06/16/2011Künstlerhaus, München

  2. Are the Charmonium(-like) States („XYZ“) Charmonium States, or not?(see plenary talks by De Fazio, Eidelman, Gao, Springer, Patriagni, and several parallel talks) Here: charmonium mass region only

  3. Is the Charmonium Potential Modelappropriate for explaining XYZ states? S > 1 at large radiusnon-perturbative? string breaking regimestill bound state? confinement(scalar ?) QCD vacuum is 3P0(„Lamb shift“ of c0 ?) 2-gluon exchange? 3 gluon vertex in hadronic decays? molecular potential? [cc]8 + gluon hybrid?(color octet) asymptotic free?(why annihilation branching so high?) contact term (spin-spin)

  4. Outline • c and c´ • mass • width • X(3872) • mass • width • quantum numbers • c2 production in B decays

  5. c andc´

  6. c • Ground state of CharmoniumJPC=0−+, 11S0 • Observed e.g. in J/ and ´radiative decays, but cross section varies according to Ea, a=3…7→ modifies lineshape→ width determination non-trivial(new Bes-III result shownat this conference) • In  → c and B decays: Breit-Wigner line shape is appropriate approximation Belle, 395/fb Eur. Phys. J. C53(2008)1 BaBar, 469/fbPhys. Rev. D81(2010)052010 c c0 c2 J/ c

  7. LEES et al., BaBar, Phys. Rev. D81(2010)052010 PDG2010 Width Mass ' 15 MeV in J/ and ´radiative decays ' 30 MeV in B decays and 

  8. arXiv: 1105.0978 submitted to PLB New mass and width measurement for c in B decays 2-dim fit of angle(K+ KS) vs. M(KSK  ) M = 2985.4 ± 1.5 −2.0+0.2 MeV  = 35.1 ± 3.1 −1.6+1.0 MeV B+ K+c, c KS K±¨ non-resonantcharmlessB decays Agreement with BaBar resultin  c Agreement with Bes-III resultin ´  cshown at this conference

  9. c(2S) 1st radial excited stateJPC=0−+, 21S0

  10. arXiv: 1105.0978 submitted to PLB New mass and width measurement of c(2S) in B decays Interference of signal and non-resonant background important fit with interference  = 6.6−5.1+8.4(stat.+model)−0.9+2.6(syst.) MeV fit w/o interference  = 41.1± 12.0(stat.)−10.9+6.4(syst.) MeV B+ K+c(2S), c(2S) KS K±¨ ´

  11. c(2S) Error on widthimproved by factor ' 2 New Belle measurement Mass 3636.1−4.1+3.9(stat.+model)−2.0+0.5(syst.) MeV Width 6.6−5.1+8.4(stat.+model)−0.9+2.6(syst.) MeV

  12. c(1S) c(2S) Hadronic width of c(2S) must be smaller than c(1S) Potential model for c(2S)width prediction not reliable, because close toDD threshold  would be nice test for Lattice QCD 3 gluon decay not possible(parity)

  13. New results on X(3872) fulldata set 711/fb on Y(4S) re-processed data(improved low momentum tracking,reconstruction efficiency in some channels ¸20% increased)

  14. B+ MBC /GeV M(J/+− )/GeV E/GeV B0 MBC /GeV M(J/+− )/GeV E/GeV Reference Analysis: BK´, ´  J/+− Preliminary Preliminary 3-dim fit in beam constrained mass, J/+− mass and E at first, fit reference signal ´ fix core Gaussian and tail Gaussian for resolution parameters

  15. Analysis of X(3872)  J/ +− Preliminary B+ 151§15 events MBC /GeV M(J/+− )/GeV E/GeV B0 21.0§5.7 events MBC /GeV M(J/+− )/GeV E/GeV 3-dim fit with fixed resolution parameters from ´ Mass MC/data shift +0.92§0.06 MeV, measured and fixed from ´ mass

  16. X(3872) mass in p+p-J/ychannel only Belle result contains MC/data shift 0.92 § 0.006 MeV, fixed from reference channel ´ <MX>prev_WA= 3871.46 ± 0.19 MeV Here former Belle measurement3872.0 ± 0.6 ± 0.5 MeVnot considered anymore(superseded by new measurement) “Binding Energy”m(X)−m(D*0)−m(D0) becomes smaller: Old: m = −0.32 ± 0.35 MeV New: m = −0.17 ± 0.36 MeV Preliminary New w/ LHCb: m = −0.12 ± 0.35 MeV Reminder: m(deuteron) = −2.2 MeV

  17. New measurement of width of X(3872) • Previous best limitX(3872) < 2.3 MeV (90% CL) • 3-dim fits are sensitive to natural widths narrower than resolution <>'4 MeVbecause of constraints (mBC, E) • Method validated with ´width´=0.52§0.11 MeV (PDG 0.304§0.009 MeV) bias 0.23 § 0.11 MeV • procedure for upper limit:width in 3-dim fit fixednsignal and npeaking BG floating calculate likelihood • X(3872) < 0.95 MeV + bias MC (output) / MeV (input) / MeV 90% 1.2 MeV

  18. X(3872) possible Charmonium Assignment • 1++ c1´ 3P1predicted mass 3953 MeVn=2favoured by angular analysisCDF-II, PRL98(2007)132002 Belle, hep-ex/0505037 • 2−+c21D2predicted mass 3837 MeVn=1(would be a L=2 meson)favoured by X(3872)  J/  analysis BaBar, Phys. Rev. D82(2010)011101 1++ / fm−3/2 2−+ r / fm Mass predictions by Barnes, Godfrey, SwansonPhys. Rev. D72(2005)054026

  19. Angular Variables • Assume X(3872)  J/in kinematic limit:both particles at rest in X(3872) rest frame mX' m+mJ/ higher partial waves can be neglected • 1++1 amplitude L=0, S=1 • 2−+2 amplitudesL=1, S=1 or S=2 J. Rosner PRD 70(2004)092023 only normalizationfloating in fit normalization and  (complex)floating in the fit

  20. Angular Variables X X(3872) rest frame

  21. 1++ Hypothesis vs. 2−+ Hypothesis =0.69 e23° i, only value which gives >10% CL in all three plots c2/dof =1.76/4 CL=0.78 c2/dof =4.60/4 CL=0.33 | cos | | cos | c2/dof =0.56/4 CL=0.97 c2/dof =5.24/4 CL=0.26 | cos lep| | cos lep| c2/dof =3.82/4 CL=0.51 c2/dof =4.72/4 CL=0.32 | cos X| | cos X|

  22. c2 in B Decays

  23. Control signal for X(3872)  J/, Belle, arXiv:1105.0177 [hep-ex], subm. PRL B§K§c1,2 with c1,2→ J/  First Evidence for B§!c2 K§ B+ c2 c1 B+→ K+c232.8+10.9−10.2 events3.6 (stat. and syst.) B0 → K0c22.8+4.7−3.9 events0.7 (stat. and syst.) B0 c2 c1 L=1

  24. Same Analysis, but reference signal c1,2→ J/ First Evidence for B§!c2 K§ B+ c2 c1 Production of J=2, Parity=+ Charmonium in B Meson Decays0−! 0− 2+ B+→ K+c232.8+10.9−10.2 events3.6 (stat. and syst.) B0 → K0c22.8+4.7−3.9 events0.7 (stat. and syst.) B0 c2 c1

  25. Radiative Transition from c1,2 to J/ • Photon energies of transitionscomparable (E' 414 MeV ' 459 MeV)but dynamics different • Lattice QCDDudek, Edwards, ThomasPhys. Rev. D79(2009)094504( c1! J/ ) = 270(70) keV ( c2! J/ ) = 380(50) keV Transistion Formfactors E1 E1 E3 M2 M2

  26. B§K§c2 Jq=½ Jq=½ Jq=½ JW=1 Vector oraxial-vector J=0 or J=1 preferred Parity + or parity − allowed JP=1+ possible (e.g. B+! K+c1BR 4.6§0.4 x 10−4) but J=2 difficult to be generated forbidden in naïve factorization additional soft gluon requiredBauer, Stech, WirbelZ. Phys. C34(1987)103

  27. Summary • New measurement of c´width in B decays (undistorted lineshape) • New measurements of X(3872), full data set, re-processed data • New world average mass of X(3872) moves closer to DD* thresholdm=−0.12±0.35 MeV (but still negative) • X(3872) never seen in radiative decays (e.g. (4040))  mass measurement by Bes-III could provide important cross-check with independant method • New upper limit on X(3872) < 1.2 MeVfactor 2 narrower than before • further improvement  <1 MeV feasiblebut only way to reach ·100 keV cooled antiproton beam PANDA experiment >2017 More Belle Results: XYZ States, Simon Eidelman(plenary, Thursday morning) Bottomonium, Alex Kuzmin(parallel, Tuesday afternoon)Belle-II, Boris Shwartz(plenary, Friday afternoon)

  28. Backup

  29. Charmonium Excited States n · 3, L · 4 Barnes, Godfrey, Swanson, Phys. Rev. D72(2005)054026 n2S+1 L J Terra Nova Mass / GeV JPC

  30. B Factories

  31. ~952 /fbOn-resonance samples:Y(4S): 711 /fbY(5S): 121 /fbY(3S): 3.0 /fbY(2S): 24 /fbY(1S): 5.7 /fbOff-resonance: 87 /fb ~553 /fb On-resonance samples: Y(4S): 433 /fb Y(3S): 30 /fb Y(2S): 14 /fb Off-resonance: 54 /fb

  32. Production of Charmonium Double CharmoniumProduction B Decays in 2-body B decays, JPC=0− +, 1− −, 1++ in factorization limit C=+1 Initial State Radiation JPC=0++,0−+, 2++ JPC=1− − 

  33. Decays of Charmonium States 1- Annihilation EM e.g. J/!+-0 OZI suppressed J=0,1,2 Do(*) Strong ~1/S2 Do(*) Strong Strong spectatorisospin transition ?(if ()=) ~1/S2 e.g.  ´! J/+- EM radiative L=1 e.g. /!cJ

  34. Braaten, Kusunoki, Phys. Rev. D71(2005)074005

  35. B+ vs. B0 decays: mixing angle • Diquark – anti-diquark modelMaiani, Piccinini, PolosaPhys. Rev. D71(2005)014028 • Mixing occurs by gluon annihilationuu  gluon  dd • Xu (Xd) populates B+ (B0) decay

  36. Helicity amplitudes for X  J/D are Wigner functions

  37. B+ and B0 decays are quite different. Swanson, Phys. Rept. 429(2006)243 B+ = BuB0 = Bd B+! K+B0! K0(charge sign changes by W§,and changes back, ! same charge for B and K) color suppressed(color is locked by spectator quark) B0! K+ B0! K0 B+! K+ B+! K0 any combination possible color enhanced

  38. PRELIMINARY X(3872) in B+ vs. B0 decays BaBar (2.7 ± 1.6 ±0.4) MeV B(B+K+ X(3872)) x B(X(3872)  J/+−)) = (8.61±0.82±0.78) x 10−6 B(B0K0 X(3872)) x B(X(3872)  J/+−)) = (4.3±1.2±0.4) x 10−6 BaBar 0.41±0.24±0.05 for molecule expected R(X) ' 1 Braaten, Kusunoki, Phys. Rev. D71(2005)074005 Small mass difference disfavours Diquark-Antidiquark Model Maiani, Piccinini, PolosaPhys. Rev. D71(2005)014028

  39. c fit function

  40. c fit function

  41. X(3872) mass measurement syst. errors Width is upper limit  no syst. error to be given.

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