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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 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 B(0,±) → D(±,0)DsJ Data agree with JP=0+ (DsJ(2317)) and 1+ (DsJ(2460)) Br(B→D-DsJ+(2317))=(10.3±2.2±3.1)x10-4 B. Golob, Belle Cracow Epiphany Conference, 2005

  7. DsJ states First observation of B0→DsJ+K- 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(B→D-DsJ+(2317))∙Br(DsJ(2317)+→Ds+p0) DsJ Br(B→D-Ds+) d DsJ(2317)→Dsp0 (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- = 0.13 ± 0.05 = 1.8 ± 0.6 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. 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. consistent with 0 First observation of decay mode other than p+p-J/y; subtreshold decay to wJ/y (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±8 MeV G=87±22±13 MeV 58 ± 11 evts. Fit with added BW 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(3490) 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 inter.,“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. KEKB is also a great source of 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

  15. Pentaquark searches backup slide Searches in decays,“high energy” charm baryon decays, B decays Searches in secondary inter.,“low energy” S(1670)+ Xc+ Q(1540)+ 131 fb-1 Lc+ → p Ks Ks M(pKSKS) M(pKS) charm baryon decays Lc+ → pK+ K- Q*(1600)++ M(pK+) M(pK+K-) B. Golob, Belle Cracow Epiphany Conference, 2005

  16. Pentaquark searches B0  p pKS B0  p+ D(*)-p B+  p pK+ B0 pD0p B0  p+D-p 155M BB,hep-ex/0411005 backup slide 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

  17. 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

  18. Production in B decays DsJ states backup slide B(0,±)→ D*(0,±)DsJ DsJ+(2317)→ Ds+p0 DsJ+(2460)→ Ds*+p0 DsJ+(2460)→ Ds+g DE side band M(DsJ) side band All events in Mbc signal region B. Golob, Belle Cracow Epiphany Conference, 2005

  19. Production in B decays DsJ states backup slide Decay channel Br 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

  20. DsJ states First observation of B0→DsJ+K- backup slide W exchange DsJ(2317) K- 16.6±4.4 evts. DsJ(2317) p+ FSI DsJ(2460) K- tree,4 quark content DsJ(2460) p+ B. Golob, Belle Cracow Epiphany Conference, 2005

  21. Potential model prediction for cu: D** states 65M BB,PRD69,112002 backup slide B+→D-p+p+ ~1100 evts. D side band B+→D*-p+p+ D0*, D1’ broad states D1, D2* narrow states ~550 evts. Modes used: D0→K-p+, K-p+p+p- D+→K-p+p+ D*+→ D0p+ Dalitz plot analysis B. Golob, Belle Cracow Epiphany Conference, 2005

  22. D** states B+→ D-p+p+ B+→ D*-p+p+ backup slide M(Dp)min M(Dp)max D0* proj. of 4D fit D1’ proj. of 2D fit D2* D1 D2* Dv*,Bv* M(Dp)min M(Dp)min DE side band bckg. subtracted B. Golob, Belle Cracow Epiphany Conference, 2005

  23. D** states backup slide M(D0*)= 2308±17±15±28 MeV; G(D0*)= 276±21±18±60 MeV; M(D2*)= 2461.6±2.1±0.5±3.3 MeV; G(D2*)=45.6±4.4±6.5±1.6 MeV; larger than WA (23±5 MeV), but no interf. effects taken into account; Focus exp. 30.5±4.2 MeV errors: stat. syst. model varying selection; track, PID eff.; hep-ex/0011044 = 0 for default fit = 240-360 if no D0* or JP=1-,2+ fits with Dv*,Bv*,constant Br(B- → D0*p-)Br(D0*→D+p-)=(6.1±0.6±0.9±1.6)x10-4 B. Golob, Belle Cracow Epiphany Conference, 2005

  24. D** states backup slide M(D1’)= 2427±26±20±15 MeV; G(D1’)= 384±90±24±70 MeV; M(D1)= 2421.4±1.5±0.4±0.8 MeV; G(D1)=23.7±2.7±0.2±0.4 MeV; in agreement with WA = 0 for default fit = 100-170 if no D1’ or JP=1-,2+ Br(B- → D1’p-)Br(D1’→D*+p-)=(5.0±0.4±1.0±0.4)x10-4 narrow reson. (D1,D2*) comprise 36±6% of Dpp final state 63±6% of D*pp final state QCD sum rule: narrow reson. dominate D(*)pp state LEP: B→D(*)pln also not dominated by narrow reson. B. Golob, Belle Cracow Epiphany Conference, 2005

  25. X(3872) p+ p- M too low; G too small K B X angular dist’n rules out 1+- q J/y M too low; G(gJ/y) too small G(gcc1) too small; mpp wrong pp hc should dominate ppJ/y G( gcc2 & DD) too small; mpp wrong backup slide Angular distrib. for 21P1 (hc’) top+p-J/y hc” hc’ cc1’ y2 hc2 y3 expected forhc’ X |cosq| c2/nof=75/9 B. Golob, Belle Cracow Epiphany Conference, 2005

  26. B± → K± p+p-p0 J/y X(3872) signal v iii iv ii i Side regions B± → K±wJ/y wband M(p+p-p0J/y) Xband fit Mbc and DE M(p+p-p0) DEin 25 MeV bins of M(p+p-p0) Possible contr.K±wJ/y0.75 ± 0.14 B. Golob, Belle Cracow Epiphany Conference, 2005

  27. B± → K± p+p-p0 J/y X(3872) backup slide B± → K1(1270)J/y 4.3±6.2 region I M(X)-M(3p) signal region region III 6.4±5.6 Simultaneous fit to DE and Mbc distrib. for M(p+p-p0)>750 MeV non-resonant, peaking bckg. 1.3±1.0 (scaled to sig. area) signific.: main syst. uncertainty: contrib. of peaking bckg. and K±wJ/y: -20%; M(3p)>750 MeV: +25% 6.4s (5.0s if 2 events peaking backg.) B. Golob, Belle Cracow Epiphany Conference, 2005

  28. 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

  29. cc recoil spectrum X e- e+ J/y backup slide Calculate recoil mass (mass of X): Reconstruct J/y →l+l- calibrate withe+e-→(2S)  (2S) → J/y p+p- <1% bckg. Shift of Mrec againts J/y with same momentum bias found Mrec(J/) < 3 MeV/c for Mrec(J/)  3 GeV/c fitted with MC with free Mrec2 off-set M2rec=0.0100.009 GeV2/c4(data/MC); introduce momentum scale bias in MC to reproduce M2rec B. Golob, Belle Cracow Epiphany Conference, 2005

  30. cc recoil spectrum D(*) ? D(*) N=9.93.3 (4.5s) Y e- e+ J/y N=4.12.2 (2.1s) backup slide Reconstruct J/y →l+l-; D0→K-p+,D+→K-p+p+ Use events with Mrec(J/y D)≈M(D*) Calculate Mrec(J/y) (mass of resonance decaying toDD(*)) B. Golob, Belle Cracow Epiphany Conference, 2005

  31. Isotriplet of charmed baryons M(pK-p+) 275M BB,hep-ex/0412069 Lcp+ final state; Lc → pK-p+ Lcp0 Lcp- Lcp+ +p 2.8x103 evts. 2.2x103 evts. 1.5x103 evts. M(Lcp)-M(Lc) Lc++(2880)→ Lc+p+p- Sc(2800)0 M-M(Lc)= 515.4 ± 3.2+2.1-6.0 MeV Sc(2800)+M-M(Lc)= 505.4 +5.8–4.6+12.4-2.0 MeV Sc(2800)++M-M(Lc)= 514.5 ± 3.3+2.8-4.9 MeV G~61-75 MeV xp Peterson fragm. function s(e+e-→Sc(2800)X)Br(Sc(2800)→Lcp) = 2-2.6 pb (± 1-2 pb) 0.2 0.4 0.6 0.8 1.0 B. Golob, Belle Cracow Epiphany Conference, 2005

  32. Lc+ p structure Sc(2455)0 Sc(2520)0 B-→ Lc+ p p- D(1600) D(2420) 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

  33. 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 backup slide 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 bckg. param. B. Golob, Belle Cracow Epiphany Conference, 2005

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