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New Resonances at Belle

Experimental environment D sJ ’s and their properties X(3872)... ...and also Y(3940) cc recoil spectrum pentaquarks? Conclusion. New Resonances at Belle. B. Golob University of Ljubljana, Slovenia Belle Collaboration.

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New Resonances at Belle

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  1. Experimental environment • DsJ’s and their properties • X(3872)... • ...and also Y(3940) • cc recoil spectrum • pentaquarks? • Conclusion New Resonances at Belle B. Golob University of Ljubljana, Slovenia Belle Collaboration B. Golob, Belle Cracow Epiphany Conference, 2005

  2. Experimental environment Mt. Tsukuba e- KEKB B Belle Υ(4s) ~1 km in diameter > 900 pb-1/day (~1 M BB/day) e+ Integrated luminosity ∫Ldt = 255 fb-1 on reson. 30 fb-1 off reson. ~280 M BB B Oct ‘04 May ‘99 KEKB asymmetric B factory Υ(4s) B. Golob, Belle Cracow Epiphany Conference, 2005

  3. Experimental environment Central Drift Chamber e+ 3.5 GeV s(pt)/pt= 0.3% √pt2+1 3(4) layer Si vtx det. e- 8 GeV combined particle ID e(K±)~85% e(p±→K±)<~10% @ p<3.5 GeV/c Aerogel Cherenkov Counter (n=1.015- 1.030) m and KL identification (14/15 lyrs RPC+Fe) 1.5T SC solenoid EM Calorimeter CsI (16X0) B. Golob, Belle Cracow Epiphany Conference, 2005

  4. B ECM/2 signal ECM/2 U(4s) e- e+ signal B B ∑ pi, ∑ Ei continuum Experimental environment Off reson. data: continuum only On reson. data: BB (spherical) separated from continuum (jet shaped) on basis of topological variables e.g. angle between B direction and beam axis B. Golob, Belle Cracow Epiphany Conference, 2005

  5. DsJ states Production in continuum DsJ+(2460)→Ds+g DsJ*(2317)+→Ds+p0 DsJ+(2460)→Ds*+p0 3.4 3.0 Mass (GeV) 2.6 Ds*+ 2.2 Ds+ 1.8 86.9 fb-1,PRL92,012002(2004) M(DsJ(2317))=2317.2±0.5±0.9 MeV M(DsJ(2460))=2456.5±1.3±1.3 MeV Masses lower than predicted in potential models; Widths consistent with zero B. Golob, Belle Cracow Epiphany Conference, 2005

  6. DsJ states Production in B decays B → DDsJ Helicity angle: Ds DsJ B D q DsJ*(2317)+ →Ds+p0 g,p0 J=1 DsJ(2460)+ →Ds*+p0 DsJ(2460)+ →Ds+g J=1 J=2 J=0 275M BB,BELLE-CONF-0461 DsJ*(2317)+→Ds+p0 DsJ(2460)+→Ds+g Data agree with JP=0+ (DsJ(2317)) and 1+ (DsJ(2460)) Br(B0→D-DsJ*(2317)+)=(10.3±2.2±3.1)x10-4 B. Golob, Belle Cracow Epiphany Conference, 2005

  7. First observation of B0→DsJ*-K+ DsJ states M(Dsp0)-M(Ds) DE 6.8 s signif. 0.2 0.3 0.4 0.5 0.6 (GeV) -0.10 0 0.10 (GeV) c s b d u K+ Br(B0→DsJ*(2317)-K+)∙Br(DsJ*(2317)-→Ds-p0) W s Br(B0→Ds-K+) B0 d 152M BB,hep-ex/0409026 Br(B0→D-DsJ*(2317)+)∙Br(DsJ*(2317)+→Ds+p0) DsJ Br(B0→D-Ds+) d DsJ*(2317)-→Ds-p0 (Ds→fp,K*K,KSK) Br(B0→DsJ(2317)-K+)∙ Br(DsJ(2317)-→Ds-p0)= (5.3 ± 1.4± 0.7 ± 1.4)x10-5 4-quark content? <2.5x10-5 @90% CL <0.94x10-5 <0.40x10-5 B→DsJ(2317)p- B→DsJ(2460)K+ B→DsJ(2460)p- = 1.8 ± 0.6 = 0.13 ± 0.05 B. Golob, Belle Cracow Epiphany Conference, 2005

  8. Observed by Belle with 152M BB B± → K± p+p-J/y l+l- How about with 275M BB? 152M BB, PRL91,262001 (2003) 275M BB,S.Olsen,GHP’04 X(3872) Calculate Mbc in 5 MeV bins ofM(p+p-J/y) M(p+p-l+l-)-M(l+l-) 3865 MeV 48.6±7.8 evts. (>10s) M=3872.4 ±0.7 MeV 3870 MeV no. of B’s in bins of M(p+p-J/y) 3875 MeV M(p+p-l+l-) B. Golob, Belle Cracow Epiphany Conference, 2005

  9. B± → K± p+p- p0 J/y Mbc andDE in 25 MeV bins of M(p+p-p0) X(3872) -0.1 0.1 5.20 5.25 5.30 Mbc DE M(p+p-p0J/y)= M(X)± 3s no. of B’s in bins ofM(p+p-p0) 13.1±4.2 evts.(6.4s) M(p+p-p0)>750 MeV consistent with 0 First observation of decay mode other than p+p-J/y; subthreshold decay to wJ/y (expected for DD* molecule) C(X(3872))=+1 B. Golob, Belle Cracow Epiphany Conference, 2005

  10. Dalitz plot for B→ KwJ/y Y(3940) B→ Kp+p- p0 J/y B± → K* J/y; K*→ K± w Events in DE, Mbc signal region resonant structure? M2(J/yw) M(p+p-p0J/y) B→ KwJ/y M(p+p-p0) M2(Kw) For these B→ KwJ/y plot Mbc, DE in bins ofM(wJ/y) B. Golob, Belle Cracow Epiphany Conference, 2005

  11. B± → K± wJ/y No. of B’s in bins of M(wJ/y) 275M BB, hep-ex/0408126 Y(3940) 40 MeV binsM(wJ/y) 3897 MeV 3937 MeV 3977 MeV large deviations from phase space M(Y)=3943±11±13 MeV G=87±22±26 MeV 58 ± 11 evts. Fit with added BW (8.1s) Relatively large signal at lowM(wJ/y) Br(B→YK)Br(Y→wJ/y)= (7.1±1.3±3.1)x10-5 B. Golob, Belle Cracow Epiphany Conference, 2005

  12. cc recoil spectrum X e- e+ J/y hc cc0 hc(2s) well established method(e.g. double cc production) Reconstruct J/y →l+l- Calculate recoil mass (mass of X): 285 fb-1,T.Ziegler,GHP’04 new resonance N=148 ± 33 (4.5 s) M=3940 ± 11 MeV Reconstruction of additional D or D* besideJ/y→ - new resonance decays to DD*; - not seen in J/y w probably not Y(3940) confirmation of hc(2s) after 1st observation by Belle B. Golob, Belle Cracow Epiphany Conference, 2005

  13. Pentaquark searches M(pK-) y[cm] L(1520) M(pKS) x[cm] (KN+(1540)X) (KN(1520)X) < 2%(90%CL) 155M BB,hep-ex/0411005 Searches in decays,“high energy” (charm baryon,B) Searches in secondary interactions,“low energy” select pK secondary vtx detector “tomography”: M(pK-)fit with D-wave BW and treshold funct.; L parameters in agreement with PDG M(pKS) fit with 3rd order poly.and narrow sig.(2 MeV) at different m assuming Br(+→pKS)=25% B. Golob, Belle Cracow Epiphany Conference, 2005

  14. Pentaquark searches B0  p pKS B0  p+ D(*)-p B+  p pK+ B0 pD0p B0  p+D-p 155M BB,hep-ex/0411005 B decays Qc0 Q(1540)+ Qc*+ Q*(1600)++ 303 ±21 evts. M(Qc0)=3099 MeV(H1) s=3.5 MeV (det. resol.) @90% CL B. Golob, Belle Cracow Epiphany Conference, 2005

  15. KEKB is also a great source of charm& cc states • Some expected, mainly unexpected/puzzling observations/discoveries D**broad states PRD69,112002 Y(3940) hep-ex/0408126 DsJ properties BELLE-CONF-0461 hep-ex/0409026 hc(2s) PRL89,102001 PRD70,071102 PQ searches hep-ex/0411005 X(3872)→ wJ/y S.Olsen,GHP’04 Sc(2800) hep-ex/0412069 resonance in cc recoil T.Ziegler,GHP’04 Lc+ p structure hep-ex/0409005 Conclusions range of questions: understanding all properties as expected? why such properties? what are they? will be addressed as more statisticsis collected B. Golob, Belle Cracow Epiphany Conference, 2005

  16. PQbackup

  17. Pentaquark searches M(pK-) L(1520) M(pKS) (KN+(1540)X) (KN(1520)X) < 2% 155M BB,hep-ex/0411005 backup slide Searches in sec. inter. select pK secondary vtx detector “tomography”: M(pK-)fit with D-wave BW and treshold funct.; L parameters in agreement with PDG y[cm] Q(1540)+ M(pKS) fit with 3rd order poly. and narrow sig. (2 MeV) at different m x[cm] @90% CL assuming Br(+→pKS)=25% m B. Golob, Belle Cracow Epiphany Conference, 2005

  18. Pentaquark searches L(1520) p p formation p(pK-)~500 MeV K- K- L(1520) p p production majority K- K- assuming Br(+→pKS)=25% Br((1520)→pK-)= 0.5 Br((1520)X→NK) ratio of e from MC (KN+(1540)X) (KN(1520)X) < 2%(90%CL) backup slide L(1520) spectrum (fit to M(pK-) in mom. bins formation p non-zero strangeness most pK vtx produced by strange particles vtx with addit. track distance pK- vtx – next track distance pK- vtx – next K+ cm B. Golob, Belle Cracow Epiphany Conference, 2005

  19. DsJ backup

  20. Production in B decays DsJ states backup slide Decay channel Br[10-4] signif. B  D DsJ(2317) [Dsp0] 10.1  1.5  3.0 9.5s B  D DsJ(2317) [Ds*g] 4.0-1.4+1.5 (<8.4) 3.5s B  D DsJ(2460) [Ds*p0] 14.8-2.5+2.8  4.4 8.6s B  D DsJ(2460) [Dsg] 6.4  0.8  1.9 11s B  D DsJ(2460) [Ds*g] 2.6-1.0+1.1 (<5.7) 3.0s B  D DsJ(2460) [Dsp+p-] 1.0-0.4+0.5 (<2.3) 2.6s B  D DsJ(2460) [Dsp0] 0.2-0.5+0.7 (<1.7) -- B  D* DsJ(2317) [Dsp0] 3.1-1.7+2.1 (<8.5) 2.0s B  D* DsJ(2460) [Ds*p0] 28.7-6.4+7.4  8.6 6.9s B  D* DsJ(2460) [Dsg] 12.7-2.0+2.2  3.8 10s Br(DsJ(2460)→Ds+g)/Br(DsJ(2460)→Ds*+p0)=0.43±0.08±0.04 Br’s from DE fits in Mbc and M(DsJ) signal region Largest syst. uncertainty from p0 eff. and D branching fractions B. Golob, Belle Cracow Epiphany Conference, 2005

  21. Y(3940) backup

  22. Y(3940) backup slide B→ KwJ/y DE in 40 MeV bins ofM(wJ/y) |DE| < 0.03 GeV, 5.2725< Mbc< 5.2875 GeV all fits consistent yield within stat. error (~200±20) B yield inM(wJ/y) bins for B→ KwJ/y phase space MC Yields determined from simultaneous DE and Mbc fits (constrained to be equal); peak position and width from fits to integrated distrib. Fit with f(M)=Aq*(M) q*(M): mom. of daughter part. in wJ/y frame B. Golob, Belle Cracow Epiphany Conference, 2005

  23. Nw=74±14 Y(3940) backup slide B→ KwJ/y M(p+p-p0) DE, Mbc signal region 20% variation included in syst. error. Ks,K± yields consistent with acc. ratio. acceptance K± KS M(wJ/y) M(wJ/y)<3997 MeV (first 3 bins in M(wJ/y)); no resonance in Kw in this M(wJ/y) region M(Kw) DE, Mbc side band: Nw=14±10(non-w 3p) fraction of true w in signal: 0.90±0.18 (in syst. error) B. Golob, Belle Cracow Epiphany Conference, 2005

  24. Y(3940) backup slide B→ KwJ/y Main syst. uncertainty: fit using S-wave BW or Lorentzian shape for resonance; linear or 3rd order polynomial for bckg.; largest deviation +38% possible non-w 3p contribution; -28% Significance: integral of fitted phase space in first 3 bins of M(wJ/y) 16.8±1.4 total number of events: 55.6 significance > 9s > 8s B. Golob, Belle Cracow Epiphany Conference, 2005

  25. Lcp structure backup

  26. Lc+ p structure Sc(2455)0 Sc(2520)0 B-→ Lc+ p p- D(1600) D(2420) 152M BB,hep-ex/0409005 3-body baryon production in B decays: baryon-antibaryon system peaked near treshold Fits to DE in mass bins 264±20 evts. Lc+ →pK-p+,pKS,Lp+, pKSp+p-,Lp+p+p- L→ pp- BW peak + feed down fromB-→ Lc+ D M = 3.35 ± 0.02 GeV 50 ± 10 evts.(5.6 s) G~70 MeV B. Golob, Belle Cracow Epiphany Conference, 2005

  27. Lc+ p Lc+ p structure Br(B-→ Sc(2455)0 p)=(3.67+0.74-0.66 ± 0.36 ± 0.95)∙10-5 Br(B-→ (Lc+ p)p-)=(3.87+0.77-0.72 ± 0.43 ± 1.01)∙10-5 Sc(2455)0 p Sc(2455)0 p simultaneous fit to 6 DE distrib.; Ni=SjeijYj Lc+ D(2420) Lc+ D(1600) Lc+ D(1232) due toBr( Lc+ → pK-p+ ) M=3.35 +0.01-0.02 ± 0.02 GeV G=0.07 +0.04-0.03± 0.04 GeV from different bkgd. param. B. Golob, Belle Cracow Epiphany Conference, 2005

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