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Determination of the J PC of the X(3872) (Reviews of BN800)

Determination of the J PC of the X(3872) (Reviews of BN800). S.L. Olsen & S.K. Choi. Apr 06, 2005 Belle General Meeting. J PC possibilities for J ≤ 2. P-viol’n & DD -allowed J PC s unlikely (reduce type size of these entries by x1/2). Use e7 – e37 data (include B K S p + p - J/ y ).

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Determination of the J PC of the X(3872) (Reviews of BN800)

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  1. Determination of the JPC of the X(3872)(Reviews of BN800) S.L. Olsen & S.K. Choi Apr 06, 2005 Belle General Meeting

  2. JPC possibilities for J ≤ 2

  3. P-viol’n & DD-allowed JPCs unlikely(reduce type size of these entries by x1/2)

  4. Use e7 – e37 data(include BKS p+p-J/y) Signal (47 ev) Sidebands (114/10 = 11.4 ev)

  5. Product BF determination Br(BKX(3872)) x Br(XppJ/y) Use PDG for y’ = (1.31±0.24(stat)±0.13(syst))x10-5

  6. Areas of investigation • Search for radiative decay • Angular correlations • Fits to the M(pipi) distribution

  7. Search for X(3872)g J/y

  8. Select BK J/yg(include both K± & Ks) • Tight J/y cuts • K± id>0.5 / Belle-standard “good Ks” • Eg>40 MeV • p0 veto (c2>4.0) • K* veto (M(Kg)>1.0 GeV) • R2<0.4; |cosqB| < 0.8 • |Mbc – 5.28|<0.0055 GeV (2s) • |DE|<0.034 GeV (2s) • E7  E37

  9. M(g J/y) Use these fits to get means & sigmas for Mbc and DE Of X(3872) BKcc1; cc1g J/y |M(gJ/y) – mcc1| < 25 MeV (± 2.4s) X(3872)?

  10. Mbc & DE for 64 MeV-wide M(gJ/y) bins Background 2.6±0.6 Prob : 13.6 <2x10-5 Nev(X3872) = 13.6±4.4 5.7s significance

  11. Product BF determination Br(BKX(3872)) x Br(Xg J/y) Nev(Xg J/y) NBBBr(J/yl +l-) e(Xg J/y) = MC:0.19±0.01 = (1.8 ± 0. 6(stat) ± 0.1(syst)) x 10-6

  12. Evidence for X(3872)p+p-p0 J/y( reported last summer hep-ex/0408116 also BN 761) 12.4 ± 4.2 evts >755 MeV B-meson yields vs M(p+p-p0)

  13. C = -1 is ruled outreduce typesize of C=-1 entries

  14. Angular Correlations Changes from BAM - Use EvtGen to generate different JPC scenarios. (Thanks to help from Ishikawa-san.) - Use likelihood (<-c2 ) recommended by PDG (& Golob) for low statistics measurements

  15. Strategy: for each JPC, find a distrib 0if we see any events there, we can rule it out example1--: sin2qKm qKm K compute angles in J/y restframe D.V. Bugg hep-ph/0410168v2

  16. y’: c2/dof = 16.3/9 y’is 1-- signal MC + background histogram c2/dof = 45.1/9 for X(3872) events background scaled from sidebands Expect 4 bin Prob : 16 evts ~5x10-5 |cosqKl| X(3872) is not 1-- !

  17. 1+- and 2-- For the y’p+p-J/y, this should be ~flat K X qJ/y J/y use J/y helicity angle qJ/y |cosqJ/y|

  18. c2/dof =31.6 /9 1+-: sin2qJ/y rule out 1+- 2-- unlikely 2--: sin2qJ/y cos2qJ/y c2/dof =19.5 /9 |cosqJ/y|

  19. 0-+ Rosner(PRD 70 094023) 0-+ : sin2q sin2y c2/dof=17.7/9 q |cosq| c2/dof=34.2/9 y safe to rule out 0-+ |cosy|

  20. 0 ++Rosner(PRD 70 094023) again In the limit where X(3872), pp, & J/y rest frames coincide: dG/dcosqlp sin2qlp c2/dof = 30.1/9 qlp c2/dof = 41.0/9 rule out 0++ |cosqlp|

  21. 1++ 1++: sin2ql sin2c Rosner (PRD 70 094023) ql K c

  22. compute q in X and J/y rest frame compute c in X and pp rest frame c2/dof = 11.4/9 c2/dof = 5.0/9 c2/dof = 10.0/9 c2/dof = 13.5/9 |cosql| |cosc| 1++ looks okay!

  23. Reduce type size for JPC values that fail angle tests

  24. Remaining states • 1++r & J/y in an S-wave • 2-+ “ “ a P-wave

  25. Fits to the M(pp)Distribution J/y XrJ/y in P-wave has a q*3 centrifugal barrier q* X r q*

  26. M(pp)- dependence of the detection efficiency

  27. M(pp) can distinguish r-J/y S- & P-waves P-wave: c2/dof = 71.0/39 S-wave: c2/dof = 43.1/39 (CL=0.1%) (CL= 28%) q* roll-off q*3 roll-off Shape of M(pp) distribution near the kinematic limit favors S-wave

  28. r-J/y in a P-wave is unlikelyreduce type-size of all J-+ entries

  29. Could the X(3872) be the cc1’ ? • Mass is way off: 3872 vs 3929  3990 MeV • we measure • Rough Expectation for pure charmonium theory range Barnes, Godfrey hep-ph/0311162 G(23P1 g J/y) ~ 11 keV G(23P1 ppJ/y) ~ G(y’ po J/y) ~ 0 (0.3 keV) ~ 30 isospin violating 0.14+-0.05 is too small compare to 30 cc1’ component of the X(3872) must be small

  30. Summary • 1++ passes all the tests • consistent with observations of: X g J/y & X”w” J/y • angular distributions & M(pp) fitted well • cc1’ assignment unlikely (Br(gJ/y) is too small) • DD* molecule models favor 1++ • Tornqvist hep-ph/0308277 • Swanson PLB588, 189(2004) • 2++ : this is ruled out by Garima et al & Jolanta et al by observation of X DD* ( but not by this analysis)

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