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Spectroscopy and New Resonances at Belle

Spectroscopy and New Resonances at Belle. B. Golob University of Ljubljana, Slovenia Belle Collaboration. Experimental environment X(3872) quant. numbers gg → Z(3930) - c c2 ’ Y(3940) X(3940) Summary. Tega verjetno ne, bom preveril z Galino.

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Spectroscopy and New Resonances at Belle

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  1. Spectroscopy and New Resonances at Belle B. Golob University of Ljubljana, Slovenia Belle Collaboration • Experimental environment • X(3872) quant. numbers • gg →Z(3930) -cc2’ • Y(3940) • X(3940) • Summary Tega verjetno ne, bom preveril z Galino B. Golob, Belle Lake Louise Winter Inst., 2006

  2. Experimental environment Mt. Tsukuba KEKB Belle u,d,s,c ~1 km in diameter > 1 fb-1/day (>1 M BB/day) Integrated luminosity ∫Ldt ~500 fb-1 on reson. 50 fb-1 off reson. ~550 M BB B Feb ‘06 May ‘99 KEKB asymmetric B factory Belle B e+ Υ(4s) e- u,d,s,c e+ g* e- 8 GeV e- 3.5 GeV e+ available data B. Golob, Belle Lake Louise Winter Inst., 2006

  3. Observed by Belle 275M BB,hep-ex/0505037 275M BB,hep-ex/0505038 X(3872) 152M BB,PRL91,262001(2003) B± → K± gJ/y B± → K± p+p-J/y B± → K± cc1(gJ/y) calibration mode, p0 veto world average: M=3871.9±0.5 MeV/c2 y’ X(3872) no. of B’s in bins ofM(gJ/y) 13.6±4.4 evts.(4s) M=3872 MeV/c2 s=13 MeV/c2 M(p+p-l+l-)-M(l+l-) Br(B→XK) Br(X→p+p-J/y) = (1.31±0.24±0.13)x10-5 charmonium, DD*, tetraquarks...? E.S.Swanson,PLB588,189(2004) L.Maiani et al.,PRD71,014028(2005) C(X(3872))=+1 B. Golob, Belle Lake Louise Winter Inst., 2006

  4. p+ X(3872) X(J/y, r) q l- l+ p- JPC=1++ p- X(J/y, r) q B K |cosq| p+ 275M BB,hep-ex/0505038 • X→gJ/y • ang. distrib. • M(p+p-) in X→p+p-J/y disfavor all of J=0,1,2 cc states except • 1++, 2++ • X→D0D0p0 ?? • 1++ →DD* S-wave • 2++ →DD* D-wave, • suppressed by • (q*)2L+1 angular distributions in B± → K± X(p+p-J/y) examples: expected JPC=0++ c2/nof=31/9 side band |cosq| c2/nof=5/9 X→ J/y r, S-wave B. Golob, Belle Lake Louise Winter Inst., 2006

  5. X(3872) N=12.5±3.9 (>5) B→KD0D0p0/KD0D*0 M(D0D0p0) in B signal region Uporabi hep-ex/0606055! preliminary Br(BK X)Br(XDD) =(1.6±0.4±0.3)10-4 M(D0D0p0) ≈ M(X) Br(XDD)/Br(X→p+p-J/y) =12±5 hard to accomodate with a 2++ state JPC(X(3872))=1++ B. Golob, Belle Lake Louise Winter Inst., 2006

  6. 395fb-1,hep-ex/0512035 acc. to PRL e+ g D D g e- • un-tagged • D0→Kp, Kpp0, K3p D+→Kpp • pt(DD)<0.05 GeV/c 64±18 evts M=3929±5±2 MeV/c2 G=29±10±2 MeV M(DD)[GeV/c2] D side band Z ≡ cc2’ 23P2 cc Z(3930) q*: D,beam axis in gg frame acceptance corrected J=2 expect. c2/nof=1.9/9 J=0 expect. c2/nof=23.4/9 D side band 5.3s S.Godfrey,N.Isgur,PRD32,189 (1985) C.R.Münz,Nucl.Phys.A609,364 (1996) B. Golob, Belle Lake Louise Winter Inst., 2006

  7. Y(3940) 275M BB, PRL94, 182002(2005) Dalitz plot for B→ KwJ/y M(Y)=3943±11±13 MeV G=87±22±26 MeV 58 ± 11 evts. >8s No. of B’s in bins of M(wJ/y) B± → K* J/y; K*→ K± w resonant structure? M2(J/yw) Br(B→YK) Br(Y→wJ/y)= (7.1±1.3±3.1) x10-5 M(J/yw) M2(Kw) radially excited P-wave cc? large Br(Y→wJ/y) cc-gluon hybrid? suppressed D(*)D(*) decays predicted M≥4.3 GeV F.E.Close,P.R.Page, Nucl.Phys.B443,233(1995) C.Banner et al., PRD56,7039(1997) B. Golob, Belle Lake Louise Winter Inst., 2006

  8. X(3940) 357fb-1,hep-ex/0507019 subm. to PRL X(3940)→D(*)D ? reconstruct J/y + one D constrain Mrec(J/y D)=M(D(*)) s(Mrec(J/y))~10 MeV/c2 X e- e+ J/y Reconstruct J/y →l+l- recoil mass (mass of X): Mrec(J/y D)=M(D) 266±63 evts M~3936 MeV/c2 s(Mrec)~ 30 MeV/c2 Mrec(J/y D)=M(D*) 24.5±6.9 evts 5s 5s M=3943±6±6 MeV/c2 G<52 MeV @90% C.L. B. Golob, Belle Lake Louise Winter Inst., 2006

  9. 357fb-1,hep-ex/0507019 subm. to PRL X(3940) inclusive/D*D tagged sample, common evts removed B>2(X→D*D) > 45% @90% C.L. B(X→D D) < 41% @90% C.L. B(X→J/y w) < 26% @90% C.L. no evidence for X(3940)→J/y w X(3940)≠Y(3940) several speculations on X(3940) nature, all pro’s and con’s; further experimental study (ang. distrib.) B. Golob, Belle Lake Louise Winter Inst., 2006

  10. Summary • KEKBis also a great source of charm & cc states • Some expected, manyunexpected/puzzling observations/discoveries cc2’ DsJ Sc(2800) Y(3940) X(3872) PQ broad D** X(3940) understanding range of questions: existence? all properties as expected? what are they? anomalous properties? B. Golob, Belle Lake Louise Winter Inst., 2006

  11. Experimental environment Mt. Tsukuba e- KEKB B Belle Υ(4s) ~1 km in diameter > 1 fb-1/day (>1 M BB/day) e+ Integrated luminosity ∫Ldt = 415 fb-1 on reson. 45 fb-1 off reson. ~450 M BB B Feb ‘06 May ‘99 KEKB asymmetric B factory Υ(4s) available data B. Golob, Belle Lake Louise Winter Inst., 2006

  12. 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 Lake Louise Winter Inst., 2006

  13. 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 Lake Louise Winter Inst., 2006

  14. X(3872) backup

  15. X(3872) cc spectrum backup slide hc” cc1’ y2 y3 hc’ MD+MD* hc2 y” 2MD y’ hc’ cc2 G parities: hc”+1 cc1’+1 hc2+1 hc’-1 y2-1 y3 -1 p+p-J/y -1 G=(-1)L+S+I hc cc1 cc0 J/y hc

  16. 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,hep-ex/0505038 X(3872) Calculate Mbc in 5 MeV bins ofM(p+p-J/y) M(p+p-l+l-)-M(l+l-) 3865 MeV no. of B’s inbins ofM(p+p-J/y) 3870 MeV 49.1±8.4 evts. Br(B→XK) Br(X→ p+p-J/y) = 3875 MeV (1.31±0.24±0.13) x10-5 M(p+p-l+l-) B. Golob, Belle Lake Louise Winter Inst., 2006

  17. X(3872) B± → K± gJ/y M=3872 MeV s=13 MeV (cc1) no. of B’s inbins ofM(gJ/y) 13.6-2.6=11.6 evts s=13 MeV no evidence, consistent significance: nbkg=2.6+0.6, nmax: best fit in X(3872) mass bin; PPoiss(nbkg>13) = 2.4x10-5 (>5s) B. Golob, Belle Lake Louise Winter Inst., 2006

  18. 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 Lake Louise Winter Inst., 2006

  19. 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

  20. 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% nbkg=2.1+1.0, nmax: best fit in X(3872) mass bin;

  21. X(3872) ccuu=1/√2 cc [1/√2 (uu+dd)+1/√2 (uu-dd)] =1/√2(|I=0>+|I=1>) backup slide M(pp) for B→XK, X→ppJ/y S-wave, c2/nof=43/39 X→J/y r (as indicated by m(pp)) P-wave, c2/nof=71/39 P=+1 S- or D-wave J/y r P=-1 P- or F-wave J/y r M(pp): centrifugal barrier suppression (q*J/y)2L+1 DE, Mbc side band I(r)=1, I(w)=0, I(J/y)=0 → X decays break isospin symmetry

  22. X(3872) JPC=0--:exotic, violates P, wrong C 0-+:ang. dist., M(pp), no gJ/y E1 trans. 0++:ang. dist., DD allowed 0+-:exotic, wrong C 1--:wrong C, ang. dist., DD allowed 1-+:exotic, M(pp), no gJ/y E1 trans., DD allowed 1++:- 1+-:wrong C, ang. dist. 2--:wrong C 2-+:M(pp), no gJ/y E1 trans., 2++:DD allowed but L=2 suppressed 2+-:wrong C, DD allowed 2++: cc2’ (=Z), M=3929 MeV/c2 1++: cc1’, M~3950-3990 MeV/c2 (potential models, ?) two orders lower than expected forcc1’ , cc2’

  23. X(3872) 447M BB B→KD0D0p0/KD0D*0 M(D0D0p0) in B signal region preliminary B meson yield in M(D0D0p0) signal region 24.1±6.1 evts 6.5s Br(BK X)Br(XDD)= (1.21±0.29±0.20)10-4 M(D0D0p0) =M(X) Br(XDD)/Br(X→p+p-J/y) =9.2±3.3 hard to accomodate by 2++ state JPC(X(3872))=1++ B. Golob, Belle Lake Louise Winter Inst., 2006

  24. X(3872) B→KD0D0p0/KD0D*0 M(D0D0p0) vs. DE B meson yields in bins of M(D0D0p0) • final signal yield from 2D • unbinned extended ML fit; • signal: double Gaussian in DE, • fixed parameters; • single Gaussian in M(D0D0p0), free • bkg: • non-resonant B→KD0D*0:double • Gauss in DE, threshold in M(D0D0p0) • - combinatorial: linear in DE, • threshold in M(D0D0p0),

  25. X(3872) B→KD0D0p0/KD0D*0 contribution of non-resonant B→KD0D*0 to M(D0D0p0) signal region: 1.6±0.2 evts (from large MC sample) mass of observed peak: M(D0D0p0)=3875.2±0.7 MeV/c2 small PS: D0p0 mass inB→KD0D0p0 also clustering at M(D*0) cross-checks: no peaking in B→KD0D-p0 B→KD0D0p0 D side band DE side band Br(B+K+ X)Br(XDD)= (1.07±0.31±0.19)10-4 Br(B0K0 X)Br(XDD)= (1.78±0.72±0.34)10-4

  26. E.S.Swanson,hep-ph/0601110 X(3872) • Tetraquarks? • X±: [cu][cd], [cd][cu] → not observed • X0: mixture [cu][cu], [cd][cd], dM ~ 8 MeV/c2 dM from B0 and B+ decays: ~2 MeV/c2 (BaBar, Beijing05) • equal production rate B0→K-X+, B0→K0Xd, B+→K+Xu, B+→K0X+, (discussion about that?), B0→XK0/B+→XK+ = 0.5 ± 0.3 • [cs][cs] partner, not seen in B→J/y f K, • DD* molecule? • JPC = 1++ • M(pp) r • comparable rJ/y, wJ/y • B0→XK0 / B+→XK+ ~ 0.06-0.29 • X→D0D0p0 / X→ p+p- J/y ~ 0.08

  27. cc2’ backup

  28. cc2’ 395fb-1,hep-ex/0512035 acc. to PRL pt(DD)[GeV/c] D0D0 MC gg→DD D(*)D* non-c bkg D+D- • Fit: signal BW (s=3 MeV/c2 included) • e dependence on M and gg lumin. func. included • bkg M-a Systematics: M, G: m(D), BW(J=0,2) Ggg: reconstr. eff., selection eff., D Br’s D side, D signal ≈ both D side B. Golob, Belle Lake Louise Winter Inst., 2006

  29. Y(3940) backup

  30. 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

  31. 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 Lake Louise Winter Inst., 2006

  32. 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)

  33. 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

  34. X(3940) backup

  35. 357fb-1,hep-ex/0507019 submm. to PRL X(3940) 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

  36. 357fb-1,hep-ex/0507019 submm. to PRL X(3940) reconstr. D can be X(3940)→D*(→Dp)D; in either case constraint Mrec(J/yD) ~ M(D*) is ok, small PS for X(3940)→D*(→Dp)D and D*→Dp X(3940)→D(*)D ? reconstruct J/y + one D Mrec(J/yD) ~ M(D(*)) constrain Mrec(J/yD)=M(D(*)) s(Mrec(J/y))~10 MeV/c2 X(3940)→J/yw ? recon. w and one J/y; Mrec(J/yw)~M(J/y) Mrec(J/yD0(±)) D side band N(DD)=86±17 N(D*D)=55±18 (shapes fixed from MC e+e-→J/yDD, e+e-→J/yD*D, e+e-→J/yD*D*) signal shape from D*D tagged sample N<7.4 @90% C.L.

  37. 357fb-1,hep-ex/0507019 submm. to PRL X(3940) J/yDD J/yDD* 266±63 evts 5s bkg: polynomial+DD threshold (e+e-→J/yDD observed); signif. of threshold 2.3 s; if removed signal signif. 5.6 s combined signif. inclusive/tag (veto tag in inclusive) 5.9s (most conservative bkg) BWG(MC s=10 MeV/c2) for J/yDD fixed to J/yDD* systematics on M: ±5 MeV/c2 fitting ±3 MeV/c2 mass scale inclusive yield:sBorn(e+e-→J/yX) x B>2=10.6±2.5±2.4 fb

  38. 357fb-1,hep-ex/0507019 submm. to PRL X(3940) inclusively reconstructed, f(‘) fraction of all with > 2 charged DD* tagged measured fraction of X(3940) decays to DD* among all > 2 body decays f/f’ > 1 => DD branching fraction Ecutoff: cut on ISR g energ. (ds/dW)meas Ecutoff independ., model depend. Ecutoff=10 MeV, q2=10.6 GeV  f=0.525 reduce model depend.  (ds/dW)Born (s for process w/o ISR, non-physical, easier comparison to theory) Ecutoff=10 MeV  fBorn(Ecutoff)=0.63 (BN636, eq. (5))

  39. 357fb-1,hep-ex/0507019 submm. to PRL X(3940) sBorn(e+e- →J/y Hcc)xB>2 [fb]: hep-ex/0507019, hep-ex/0412041 NRQCD, hep-ph/0601110 light cone, hep-ph/0601110

  40. 357fb-1,hep-ex/0507019 submm. to PRL X(3940) largest systematics on sBorn and Br: - fitting (range, DD*, D*D* threshold) - X spin (0,1,2); different BW, different ang. distrib. (efficiency), J/y prod. and helicity angles varied X(3940)=cc1’? DD* mode dominant no cc1 in Mrec X(3940)=hc’’? expected mass 4040-4060 MeV/c2 E.S.Swanson,hep-ph/0601110

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