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The International Light-Cone Workshop July 7, 2005 Cairns, Australia

Hadron Spectroscopy at BABAR BY Usha Mallik (University of Iowa) Representing The BaBar Collaboration. The International Light-Cone Workshop July 7, 2005 Cairns, Australia. Topics:. Hadron Spectroscopy: D s (cs) States : Inclusive and Exclusive studies

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The International Light-Cone Workshop July 7, 2005 Cairns, Australia

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  1. Hadron Spectroscopy at BABARBYUsha Mallik (University of Iowa)RepresentingThe BaBar Collaboration The International Light-Cone Workshop July 7, 2005 Cairns, Australia

  2. Topics: • Hadron Spectroscopy: • Ds (cs) States : Inclusive and Exclusive studies • Double Charmonium Production; the X and the Y • Pentaquarks • Charmed Baryon studies • Summary • What can we learn from each other ?

  3. The BABAR Detector at PEP-II and the Dataset And Much More Ecm = 10.58 GeV Plan to Double Dataset by Next Summer

  4. DSJ (cs) Spectroscopy • New States DSJ(2317)+ and DSJ(2460)+ • First Observed Inclusively in e+e- Collisions • Previously Established States with Likely JPC DS (2112)+  1-(+) S-Wave (c and s spins aligned) Ds alsoDS 0 Ground State DS(1969)+: JP=0-, c and s spins opposite, in S-wave DS(2536)+  1+(+) P-Wave (needs confirmation) D*(2010)+K0 D*(2007)0K+ DS(2573)+ 2+(+) D-Wave (consistent with) D0K+

  5. Discovery of DsJ States e+e-  cc  DsJ + X DsJ(2460)+ Ds*+0 Ds* Ds DsJ(2317)+ Ds+0 Discovery Caution: These Decays cross-feed M(2460) – M(2112) BABAR, BELLE, CLEO mutually confirm, also CDF (2317) BaBar 125 fb-1 Belle 87 fb-1

  6. (also D-Wave) • Decays violate isospin: mixing • Look for radiative and dipion transitions • If is , expect is forbidden is forbidden • If is , expect is allowed is allowed (for a conventional meson)

  7. Belle 87 fb-1 BaBar 125 fb-1 Search for DsJ→Ds Excludes 0±if present BABAR DsJ(2317): compatiblewith 0+ DsJ(2460): 0± excluded BABAR: PRD 69 (2004) 031101 (R) ; BELLE : PRL 92 (2004) 012002

  8. DsJ(2460) DsJ(2460) → Ds0Kinematics BABAR hep-ex/0408067

  9. BELLE: PRL 91 (2003)262002

  10. Exclusive Production of D*SJ in B ->DSJ(*)+ D(*) Reconstruct one B: other is a B for Study • Kinematic Constraints Help, Even though Lower Stats • Reduces Backgrounds • Measure Ratios of Branching Fractions • Measure Br • Well-defined Initial State • Test DSJ(*) Spin Assignments

  11. B  DsJ (*)+D(*) BABAR: PRL 93 (2004) 181801 Data sample: 122 million B pairs m(DsJ) mES DsJ*(2317)+  Dsp0 Full reconstruction of the exclusive B decay DsJ(2460)+  Ds*p0 Sum over charged and neutral B’s 112 ± 14 events We measure: DsJ(2460)+ Dsg 139 ± 17events BABAR mES m(DsJ)

  12. B  DsJ (*)+D* Results BABAR m(Ds+p0) m(Ds*+p0) m(Dsg ) B0 DsJ(2317) B0 B0 DsJ(2460) DsJ(2460) B+ B+ B+ B.F. Products for BDsJ(*)+D* in agreement with Belle results BELLE: PRL 91 (2003) 262002 Data sample: ~124 million B pairs

  13. B  DsJ (*)+D Results BABAR m(Ds*+p0) m(Dsg ) m(Ds+p0) DsJ(2317) B0 B0 B0 DsJ(2460) DsJ(2460) B+ B+ B+ B.F. Products for BDsJ(*)+D in agreement with Belle results

  14. 0 h DsJ B – D Spin Analysis of B  DDSJ* • Two body decay BDDSJ forces DSJ to populate helicity zero only • Analyze angular distribution (cos h) of daughter of DSJ • BELLE Finds from Angular Distribution • DSJ(2317)* J = 0 (Preliminary)

  15. Ds qh DsJ+(2460) g BDsJ(2460)+D BABAR J=2 J=1 Data points from m(Dsg) fits corrected for detector acceptance and efficiency J=1 (c2=4.0/4) preferred to J=2 (c2=36.4/4) confirms Belle measurement

  16. Taking Stock of cs States DsJ*(2317)+, DsJ (2460)+ • Observed by BaBar, Belle and CLEO • Unexpectedly below threshold for DK and D*K, respectively • Consistent with P-wave cs states but other interpretations not ruled out • If cs, observed decays • DsJ*(2317)+ Ds+p0 • DsJ (2460)+ Ds*+p0 are isospin violating  narrow • DsJ (2460)+ Ds+g also observed (and used to determine J) DsJ(2573)+ Ds1(2536)+ Ds1(2460) Ds0(2317) Ds*+ Ds+ e.g. Godfrey-Isgur model S-wave P-wave Several other explanations exist e.g. Molecules or Hybrids

  17. New Charmonium-like States X(3872) J/π+π- CDF PRL 93 072201 (2004) Average Mass 3871.9 ± 0.5 MeV Narrow  < 2.3 MeV @ 90% CL (D0D*0 threshold at 3871.3 ± 1.0) BABAR hep-ex/0406022 BELLE PRL 92 262001 (2003) D0 PRL 93 162002 (2004)

  18. Recent Update: B+ X(3872)0K+ Reconstruction Background from B decays to same final state J/K BELLE (256 fb -1) hep-ex/0505038, BABAR hep-ex in preparation

  19. About X(3872) • Search for a Charged Partner From 212 fb -1 Data BABAR Observed No Signal for X- Phys. Rev. D71 : 031501, 2005 B(B0 X-K+, X-  J/ π-π0) < 5.4 X 10 -6 @ 90% CL B(B- X-KS, X-  J/π-π0) < 11 X 10 -6 @ 90% CL • Charmonium State : no isospin partner expected (data) • Molecule State (?) : highly suppressed B0 X(3872) predicted • Diquark-antidiquark State : different masses of X(3872) • in B0 and B+ decays predicted, |M| > 5 MeV E. Braten, M. Kusunoki hep-ph/0412268 L. Maiani, F. Piccini, A.D. Polosa, V. Riquer PRD 71(2005) 014028

  20. B0 X(3872)0KS Reconstruction Background

  21. Other searches for X(3872) BABAR Search for X(3872) in events with initial state radiation (if JPC = 1-- ) PRD 71 (2005) 052001 Search for X(3872) in B  X(3872)K in the spectrum recoiling against K from the B decays (with the other B fully reconstructed): mes of all the exclusively reconstructed B mES :B mass using beam energy Use BABAR-BELLE average BF(B+ X(3872)K+, X(3872)J/) = (13.2  2.2) x 10 -6 B(X(3872) in B  X(3872)K, X(3872)  J/) < 3.2 X 10 -4 at 90% CL and so, BF(X(3872)  J/+-)  4.3 %

  22. BELLE: 256 fb -1 4.0  C= +1 favored hep-ex/0505037 Also X(3872) π+π-π0J/ X(3872) : +- Invariant Mass Distribution BABAR: hep-ex in prep. BELLE: hep-ex/0505038 Di-pion mass consistent with 0+- , again C =+1 ; S-wave J/  favored: J++ favored over J-+ Isospin violating: predicted D0D*0 molecule, Swanson PLB 588 (2004) 189, Törnqvist PLB 590 (2004) 209

  23. 3872 M[Ge DDThreshold X(3872): BELLE Finds Data Disfavors 0++ and 2++, Leaving 1++ cc ? 1++ is c1’ X(3872) is too light

  24. Double Charmonium Production Study double charmonium in e+e- annihilation }C=+1 }C=-1 c , c , c(2S) J/, (2S) Theorists predict the cross sections of the two processes to be comparable G. T. Bodwin, E. Braaten & J. Lee PRD67, 054023 (2003)

  25. Reconstruct J/ or (2S) and Look at Recoil Mass BABAR: 124 fb -1, hep-ex/0506062 c(2S) c c0 BABAR BELLE: PRD 70 (2004) 071102

  26. Double Charmonium Production from BELLE From BELLE Evidence of X(3940): 4.5 m = 3940 ± 12 MeV,  < 96 MeV at 90% CL

  27. A Near-threshold J/ Mass Enhancement in B  KJ/ at 3940 MeV/c2 BELLE 8 : 253 fb -1 with 59 ±11 Events Dominantly cc Is it the same as X(3940) ? BELLE: Phys. Rev. Lett. 94: 182002, 2005

  28. A Broad Structure in J/π+π- Mass near 4.26 GeV e+e-  ISRJ/+-in Initial State Radiation Recoil Mass Consistent with zero BABAR: 211 fb-1 (preliminary) 125±23 excess events (2S) hep-ex/0506081, submitted to PRL

  29. In addition to (2S) a Broad Structure is Observed in ISR Events • JPC = 1-- ; Can be Characterized by a single Resonance • at 4.26 GeV and Width ~ 0.09 GeV • Too low Statistics to Discern if Multiple States together • - (e.g. S and D waves can mix) D*D* threshold BABAR 3.77 Y(4260)  J/ S-wave phase space BES, PRL 88 (2003), 101802 4.26 + - mass distribution from Y(4260) Why no rise in R ?

  30. Pentaquark searches Pentaquark discovery in 2003, ( confirmed by 13 experiments) (statistical significance of individual experiments is not high ~5-6 ) Also many negative searches reported, especially a recent high statistics study by CLAS Claims of exotic narrow baryons LEPS, CLAS, …: M=(1542±5)MeV/c2 G<21MeV/c2 NA49: M=(1862±2)MeV/c2 G<18MeV/c2 H1: M=(3099±6)MeV/c2 G<28MeV/c2 S Q5(1540)+ [uudds] I3 X5(1860)- - [ddssu] Q5c(3100)0 [uuddc] The anti-decuplet for Pentaquarks

  31. Inclusive and Exclusive Searches at BABAR 5+, 5--, 50, 5c0

  32. e+e- annihilation (~123 fb -1) hep-ex/0502004 accepted by PRL

  33. accepted by PRL

  34. Upper Limit

  35. So far, evidence of 5 claimed in • real/virtual photoproduction • hadroproduction • photoproduction No Signal Observed by CLAS in this Mode with ~40 times Statistics , now repeating other modes BABAR studies electro- and hadro-production in interactions with the material of the inner detector ; Observes no signal

  36. BABAR 230 fb -1 e+ e- Detector Tomography with pKS0 vertices

  37. Clear Ks from p+p-Decays Selected Protons Selected from Particle ID BABAR pKs mass distribution Mass resolution ~2 MeV

  38. Associate p Ks Vertex with ± and K± BABAR (1115)

  39. No Pentaquark Observed by BABAR BABAR

  40. Charmed Baryon Studies • Precision Mass Measurement of C+ (cud) • Production Process and Ratio of Branching Fractions of C0 (csd) cc or B  C0 + X • Production Process and Ratio of Branching Fractions of C0 (css) cc or B  C0 + X C0 - + - + -+ -K- + +

  41. BABAR Mass Measurement of C+ Using Low-Q-value Decay Modes of C+ KSK+ and C+ 0KSK+ BABAR Result : m(C+ ) = 2286.46 ± 0.14 MeV/c2 PDG Value 2284.9 ± 0.6 MeV/c2 m(C+KsK+ ) = 2286.501 ± 0.042 (stat.) ± 0.144 (sys.) MeV/c2 m(C+0KsK+ ) = 2286.303 ± 0.181 (stat.) ± 0.126 (sys.) MeV/c2 Cross-checks: m(LC+pKp+ )=2286.39 ± 0.12 (stat.) ± 0.45 (sys.) MeV/c2 m(C+ pKs) = 2286.36 ± 0.03 (stat.) ± 0.43 (sys.) MeV/c2 m() = 1115.68 ± 0.01 (stat.) ± 0.04 (sys.) MeV/c2 PDG Value = 1115.683 ± 0.006 MeV/c2 m(KS) = 497.56 ± 0.04 (stat.) ± 0.26 (sys.) MeV/c2 PDG Value = 497.648 ± 0.022 MeV/c2 hep-ex/0507009, submitted to PRD

  42. Goals: Measure Ratio of Decay BFs : Study Production Mechanism BABAR 116 fb -1 c0-π+ c0-K+ B(c0-K+) B(c0-π+) = 0.294 ± 0.018 ± 0.016 hep-ex/0504014, submitted to PRL

  43. BABAR Study c0 Momentum (p*) in e+e- rest frame 116 fb -1 c0-π+ c0 from B Decays c0 peak from B’s absent in off-peak hep-ex/0504014, submitted to PRL Results:  (e+e-  C0X) •B (c0 -+) = 388 ± 39(stat.) ± 41(syst.) fb Efficiency Corrected B (Bc0X) •B (c0 -+) = 2.11 ± 0.19(stat.) ± 0.25(syst.) X 10 -4

  44. Inclusive c0 Studies BABAR Branching Fractions and Production Mechanism from p* Spectrum Decay Modes of C0 Studied  -+, -+- +, and -K- ++ Results: 225 fb -1 C0-+ P* > 2.8 GeV/c SLAC-PUB-11323, hep-ex/0507011

  45. The p* Spectrum from -π+ Mode BABAR B  C0 Production (First Observation) Off-peak only On & Off-peak Not Corrected for Efficiency Analysis in Progress SLAC-PUB-11323 hep-ex/0507011

  46. Summary & Conclusion • Unfolding cs spectroscopy • New States X(3872), Y(3940)… and Y(4260)? • Copious Double Charmonium Production • Pentaquark Fading ? • Exciting Charmed Baryon Spectroscopy • What can we Provide ?

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