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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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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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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