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New Particles at BELLE

New Particles at BELLE. There is an impressive list of new particles in the charm sector discovered by BELLE in the last few years: This talk covers only Not included in this talk X(3872)  c (3753)  Phys. Rev. Lett. 89 (2002 )

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New Particles at BELLE

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  1. New Particles at BELLE There is an impressive list of new particles in the charm sector discovered by BELLE in the last few years: This talk covers onlyNot included in this talk X(3872) c(3753)  Phys. Rev. Lett. 89 (2002) X(3940) (2308) Y(3940)  Phys. Rev. Lett. 94 (2005) D1(2427) c(2800)  Phys. Rev. Lett. 94 (2005)  Phys. Rev. D 69 (2004) Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  2. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  3. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  4. Discovery of X(3872)  J/ Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl  History Discovery by BELLE : narrow+-J/ mass peak in excl. B-  K-+-J/ decays  Phys. Rev. Lett. 91, 262001 (2003) has been confirmed by CDF II, D0, BaBar m,  not compatible with charmonium state m+- peaks near upper kinematic limit as expected for   +- • but : charmonium decaying to J/ violates isospin  suppressed

  5. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl X(3872) observation

  6. Theoretical Explanation for X(3872)  What could it be? • Mx = (3871.9 ± 0.5) MeV is within error equal to the threshold (3871.3 ± 1) MeV •  Speculation: X might be a molecule - like bound state • Tornquist: JPC = 0-+, 1++ C = +1 • +-J/ via 0J/ intermediate state  m+- concentrated at high masses • Swanson: dynamical model for X as a hadronic resonance JPC = 1++ strongly favoured + appreciable admixture of J/ + small J/ Decay X(3872)  J/ observation would unambiguously establish C = 1 for X Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  7. Study of X(3872)  J/ Study B  K J/ 256 fb-1 data sample (275 M ) Selection: J/, K0 or K,  Ptab > 40 MeV to reduce continuum events (e+e-  qb) R2 < 0.4 (normalized Fox-Wolfram moment) |cosB| < 0.8 B polar angle of B in cms B  KJ/ are identified by Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  8. Evidence for X(3872)  J/ Constraint: Signal Region: Mbc > 5.20 GeV 5.2745 < Mbc < 5.2855 GeV |E| < 0.2 GeV |E| < 0.035 GeV Prominent peak near 3510 MeV in M(J/) is used for calibration The only significant B-meson signal is in the 3872 MeV bin (also for E-distribution) Simultaneous fitof Mbc and E and background (ARGUS function for Mbc and first order polynominal for E): Signal yield: 13.6 ± 4.4 events, Significance: 4.0  Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  9. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  10. 4 Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  11. Evidence for X(3872)   J/ • X  J/ • similar selection as above • slightly different signal region • only significant B-meson signal in 3872 MeV bin (not shown) • Mbc distribution for various inv. mass bins: • only significant B meson signal for M() > 750 MeV bin • the same for E • Fit: 12.4 ± 4.1 events Significance: 4.3  • possible background B  K  J/ fit: 0.75 ± 0.14 events • B  K-J/ non res., use left and right side bound region • 1.3 ± 1.0 events Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  12. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  13. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  14. triple scalar product X(3872)  +J/ A ~ J/xprel Lint p waves J/ in  rest frame  rest frame Transversity analysisuseful for decays to V + V 1-p = 4%, 0.01% Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  15. X(3872)  +J/ A ~ J/ Lint common rest frame of J/ and0 (relativ momentum maybe neglected) 1-p = 0.3%, 5x10-6 % Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  16. triple scalar product X(3872)  +J/ A ~ xJ/ Lint in X rest frame (D = 0) neglecting rel.mom. between J/ and 0 : all are in same CMS 1-p = 75%, 16% Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  17. centrifugal barrier ! X(3872)  +J/ Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  18. 3 pseudoscalars require D-wave Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  19. I-violating hadr.trans.: (2S)   J/ Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  20. X(3940) Further analysis of the processes History: first observation of such processes by BELLE Phys. Rev. Lett. 89, 142001 (2002) Theoretical calculation:  various speculations: glueball contribution ? etc. For the first time seen: X(3940) new charmonium state Look for recoil to J/and (2S) etc. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  21. double charmonium Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl Study of the decay of reconstructed (2S)  J/ search for look for recoil spectra 3 significant signals seen: (BaBar gets consistent results)

  22. Using higher statistics (287 fb) extend analysis of recoil masses against J/ above DD threshold e+e-  J/X Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl no signal of X(3872)  find new significant peak at M ~ 3.940 GeV/c2  “X(3940)” Fit: c, co, c(2S), X(3940) + background  MX = (3.937 ± 0.012) GeV/c2 compatible with 0 (< 95 MeV/c2) 90% CL <~ resolution (=32 MeV)

  23. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  24. ≠ X(3940) Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  25. Charmed baryon spectroscopy light diquark in the environment of a heavy quark  test for theoretical models PDG 2004: 4 excited charmed baryons observed c(2455) ground state c(2520) Aim : find excitations of c Analysis: uses data sample 253 fb-1 at (4S), signal window around : ± 8 MeV/c2 xp > 0.5 for candidates yield: (516 ± 2) x 1013 S/B = 2.3 combine with  xp > 0.7 cosdec > -0.4 dec = angle between ( in rest frame of ) and boost direction of the system in cms Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  26. (+) (0) (++) Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  27. Charmed baryon spectroscopy c(2800)0c(2800)+c(2800)++ Isotriplet Enhancement at M ~ 0.43 GeV for M( ) and M( +)  feed-down from decay c(2880)+  + observed by CLEO next: study +: clear peaks of c(2800)+ and c(2765)+ seen consistent with observation of CLEO Fit: Isotriplet + feed-down + combinatorial background (e+e- c(2800)X) x Br(c(2800)  ) 2.04 (0), 2.6 (+), 2.36 (++) pb Theoretical models c2 doublet with Jp = 3/2- and 5/2-c2   mainly in D wave M = 500 MeV/c2 as measured  ~ 15 MeV smaller as measured c2(JP = 3/2-) can mix with c1(JP = 3/2-) and would produce a wider physical state Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  28. Summary seen for the first time (now also BaBar) X(3940) new charmonium state c(2800) triplet established tentative identification: c2, JP = 3/2-; c1, JP = 3/2- admixture Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  29. SPARES  Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  30. qq e- e+ Other B continuum Y (4S) e+ e- - BB Signal B Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl Continuum Suppression Unwanted Background for B-Decays: Continuum e+e-qq “continuum” (~3x BB) Jet-like To suppress: use event shape variables BB spheric

  31. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl Continuum Suppression • To separate spherical BB events from jet-like continuum events, topological variables are used: • Second Fox-Wolfram moment • Super Fox-Wolfram • (six modified Fox-Wolfram moments, Fisher discriminant) • 3) Angle between B meson and • beam axis direction • 4) Angle between thrusts of • selected B meson particles and all other particles in event • Likelihood ratio includes all info.

  32. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  33. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  34. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  35. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  36. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  37. Beauty 2005 Assisi Spectroscopy and new Particles F. Mandl

  38. JPC possibilities for X(3872) • J ≤ 2 • DD allowed & P-violating unlikely • signal for X  γJ/ψ •  C=-1 ruled out • check of angular distributions •  rules out 1±-,0±+,2-- • fits of Mππ •  2-+ unlikely • X(3872) = χc1‘? •  unlikely, since mass and BR ratio way off theo. expect.

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