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New States in Charm Spectroscopy from Babar and Belle: a review

New States in Charm Spectroscopy from Babar and Belle: a review

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New States in Charm Spectroscopy from Babar and Belle: a review

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  1. New States in Charm Spectroscopyfrom Babar and Belle: a review • An Intro • DsJ Spectroscopy • X,Y,Z states • Charmed baryons • News flash from • Measurement of Spins • D0-D0 Mixing • Summary and Conclusion byUsha Mallik (The University of Iowa) International Conference on Relativistic Hadronic and Nuclear Physics – LC2007, Columbus, OH, May 14-18

  2. b b B q e+e-  (4S)  BB also cc, ss, uu, dd (4S) (10580) MeV q (5279MeV) B b b time e+e-  (bb) 1.05 nb  (cc) 1.30 nb  (uds) 2.09 nb Also a charm factory What happens at e+e- B-factory e- beam energy9.1 GeV, e+ beam energy 3 GeV, E(cm) = 10.58 GeV e- beam energy 8.0 GeV, e+ beam energy 3.5 GeV, E(cm) = 10.58 GeV

  3. BELLE AND BABAR: B AND c-FACTORIES Asymmetric e+e- collisions at 10.58 GeV Peak luminosity 17 x 1033 cm-2 s-1 Belle 710 fb-1 recorded 422 fb-1 recorded Babar

  4. Charm-strange mesons (cs) : Ds, DsJ • Ds0*(2317) and Ds1(2460): surprising states • DsJ*(2860): another new state • X(2690) and DsJ(2700): even more new states, or are they the same ?

  5. Expected spectroscopy

  6. Observed States States prior to 2003 Even for 2573: 2+ not established DSJ(2317)+ and DSJ(2460)+ observed in e+e- cc Also observed in B-decays Well-established experimentally - Masses and width -Natural JP: 0+ for Ds0*(2317) and 1+ for Ds1(2460) - Decay modes andBranching fractions • Interpretation of these new states still unclear! • One possibility : identify these 2 states as the • 0+ and 1+ cs states • However strong difficulties within the potential model • Semi-relativistic model • Other possibilities: • 4 quark states? DK molecule? D atom? Chiral symmetry? Ground State DS(1969)+: JP=0-, c and s spins opposite, in S-wave Belle: Phys. Rev. Lett. 91 (2003) 262001 BaBar: Phys. Rev. D74 (2006) 032007 Belle: Belle-Conf-0461 (2006) BaBar: Phys. Rev. D74 (2006) 031103

  7. DsJ*(2860): ANOTHER NEW STATE • Looking in cc continuum: • e+e-  D0(K-+,K-+0)K+X ande+e-  D+(K-++)K0sX D+(K-+ +)K0s D0(K-+)K+ D0(K-+ 0)K+ Ds2(2573) Ds1(2536) Ds1(2536) 240 fb-1 Ds2(2573) Ds2(2573) Ds1(2536) New state at 2860 MeV/c2! Bump at 2690 MeV/c2? BaBar: Phys. Rev. Lett. 97 (2006) 222001

  8. DsJ*(2860) AND… X(2690)? Sum of 3 modes X(2690) • Combining the 3 modes • M = (2856.6 ± 1.5 ± 5.0) MeV/c2 •  = (47 ± 7 ± 10) MeV • JP = 0+, 1-, 2+, … • Final state is DK, i.e. two pseudoscalars • Interpretation? • Radial excitation of Ds0*(2317)?hep-ph/0606110 • cs with JP = 0+?hep-ph/0608139 • cs with JP = 3-?hep-ph/0607245 • Another structure at 2690 MeV/c2? • M = (2688 ± 4 ± 3) MeV/c2 •  = (112 ± 7 ± 36) MeV • Need confirmation by other experiments… 240 fb-1 Bkg subtracted DsJ*(2860) BaBar: Phys. Rev. Lett. 97 (2006) 222001

  9. EVEN MORE STATES: DsJ(2700) D0K+ projection Dalitz plot DsJ(2700) • Study ofB+D0D0K+ • Looking at the Dalitz plot and the D0K+ projection • New resonancedecaying to D0K+ • B+D0DsJ, DsJ D0K+ • M = (2715 ± 11 +11-14) MeV/c2 •  = (115 ± 20 +36-32) MeV • JP = 1- favored • Same resonanceas seen by BaBarin continuum,X(2690)? • Mass and width not inconsistent, same decay mode • Interpretation? • cs state 23S1? • expected mass at 2720 MeV/c2 • Chiral symmetry: 1+ - 1- doubletpaired with Ds1(2536)? Phys.Polon. B 35, 2377 (2004) DsJ(2700) Background D0K+ projection 420 fb-1 DsJ(2700) bkg subtracted 414 fb-1 J=1 J=0 J=2 449 x 106 BB pairs produced Belle: hep-ex/0608031

  10. EVEN MORE STATES: DsJ(2700) • Study of B D(*)D(*)K decays in BaBar (22 modes) • Looking at 8 DK + 8 D*K invariant masses, adding 15 decay modes wrt Belle • Enhancement observed around 2700 MeV/c2in DK and D*K • Additional cs surprise? Maybe! • One or two resonances around 2.6-2.7 GeV/c2 in D*K? • Need to perform a full Dalitz plot analysis • Takes into account interferences Summing all 8 D*K modes Summing all 8 DK modes Ds1(2536) New result preliminary 347 fb-1 Phase space Background (generic MC) BaBar: preliminary

  11. CURRENT SITUATION A Very Rich Spectroscopy in cs is emerging • Ds0*(2317)+, Apr. 2003: unexpected observation of a narrow resonance in BaBar DsJ*(2860) • Ds1(2460)+, May 2003: CLEO, BaBar observed a new narrow resonance X(2690) DsJ(2700) • DsJ*(2860)+, Jul. 2006: new state discovered by BaBar Ds1(2460) Ds0*(2317) • X(2690)+, Jul. 2006: broad enhancement seen in BaBar • DsJ(2700)+, Jul. 2006: new state discovered by Belle ( X(2690)?) S wave P wave D wave

  12. NEXT: The New Charmonia(-like) States ! The Alphabet Soup ! • X(3872) • X(3940), Y(3940) and Z(3930) • Y(4260)

  13. The Charmonium(-like) States hc Below DD threshold states well understood. The X,Y,Z states are all above the threshold

  14. X(3872) X(3872)  J/+- 250 fb-1 • First observation by BELLE in B decays: B±X(3872)K± with X(3872)  J/+- • Confirmed by BaBar, CDF, D0 • M = (3871.2 ± 0.5) MeV/c2 •  < 2.3 MeV at 90% CL • Observation of B  X(3872)K, X(3872)  J/  • Implies: CX(3872)=+1 • Belle, CDF: +- inv. mass distribution + angular analyses • L(+-) = odd, I = 1  J/00 should not be observed • JPC = 1++favored • BaBar: search for a charged partner (decaying to J/0-) • No signal  I = 0  I violated in J/+- X(3872)  J/  260 fb-1 Belle: Phys. Rev. Lett. 91 (2003) 262001 Belle: hep-ex/0505038 BaBar: Phys. Rev. D73 (2006) 011101 Belle: hep-ex/0505037 BaBar: Phys. Rev. D74 (2006) 071101

  15. X(3872): STILL SOME SURPRISES • BaBar: looking at B D0D*0K (D*0 D00/) • Excess in the D0D*0 invariant mass • M = 3875.6 ± 0.7 +1.4-1.5 MeV/c2 • Belle: looking at B D0D00K • Excess in theD0D00 invariant mass • M = 3875.4 ± 0.7 +1.2-2.0 MeV/c2 414 fb-1 347 fb-1 New result preliminary • Masses between Belle and BaBarin good agreement • 2.5 away from the X(3872) world average! • If X(3872), JP = 2+disfavoredhep-ex/0606055 Belle: Phys. Rev. Lett. 97 (2006) 162002 BaBar: preliminary

  16. X(3872): INTERPRETATION • X(3872) likely not a charmonium state • Radial excitation of c1 (JPC = 1++) expected at 3950 MeV/c2 • If 3D1 or 3D2, radiative decays to  states, not observed • No satisfactory cc assignment • D0D*0molecule?Prediction:Phys. Rev. D71 (2005) 074005 • B0 X(3872)K0suppressed by a factor 10 compared to B+ X(3872)K+ • Measurements: • R(B0/B+) = 0.50 ± 0.30 ± 0.05 in B  J/+-BaBar: Phys. Rev. D73 (2006)011101 • R(B0/B+) = 2.23 ± 0.93 ± 0.55 in B D0D*0KBaBar: Preliminary • 4 quark state?Prediction: Phys. Rev. D71 (2005) 014028 • Predict 2 neutral states and 2 charged states • Neutral states produced in B0 and B+ decays: m  (7 ± 2) MeV/c2 • Measurements: • m = (2.7 ± 1.3 ± 0.2) MeV/c2 in B  J/+-BaBar: Phys. Rev. D73 (2006) 011101 • m = (0.2 ± 1.6) MeV/c2 in B D0D*0KBaBar: Preliminary • Glueball? Hybrid? …

  17. X(3940), Y(3940) AND Z(3930) Y(3940) X(3940) New state seen in e+e- J/ X Also, observed X  DD*, but not X  DD Near threshold enhancement in B  J/ K 253 fb-1 357 fb-1 M = (3943 ± 11 ± 13) MeV/c2  = (87 ± 22 ± 26) MeV cc state ’c1 [23P1]? Z(3930) New resonance state in  DD • M = (3943 ± 6 ± 6) MeV/c2  = (15.4 ± 10.1) MeV cc state c(3S) [31S0]? M = (3929 ± 5 ± 2) MeV/c2  = (29 ± 10 ± 2) MeV cc state ’c2 [23P2]? 395 fb-1 Belle: hep-ex/0507019 Belle: Phys. Rev. Lett. 94 (2005) 182002 Belle: Phys. Rev. Lett. 96 (2006) 082003

  18. Y(4260): ANOTHER MYSTERY • New resonance discovered in e+e- ISR(J/+-) by BaBar • BaBar measures: M = (4259 ± 8) MeV/c2,  = (88 ± 23) MeV • Belle measures: M = (4295 ± 10 +10-3) MeV/c2,  = (133 +26-22+13-6) MeV • Confirmed by CLEO: M = (4284 +17-16 ± 4) MeV/c2,  = (73+39-25± 5) MeV • No evidence for: • e+e- ISR(DD), e+e- ISR(+-), e+e- ISR(pp), e+e- ISR(J/) • 3 enhancement in B decays • B-YK-, YJ/+- • Needs confirmation JPC=1-- 233 fb-1 553 fb-1 BaBar: Phys. Rev. Lett. 95 (2005) 142001 Belle: hep-ex/0612006 BaBar: hep-ex/0607083 BaBar: PRD 73, 011101 (2006) Cleo-c : PRD 74, 091104 (2006)

  19. Y(4260)... AND Y(4325)? • Study of Y(4260)  (2S) in ISR production • Incompatible • with BaBar Y(4260),(4415) or 3-body phase space • Compatible • with Belle Y(“4295”) Preliminary M= (4324 ± 24) MeV/c2  = (172 ± 33) MeV 298 fb-1 BaBar: hep-ex/0610057

  20. Y(4260): INTERPRETATION • No cc assignment for 1-- state • Probably not a glueballPhys. Lett. B625 (2005) 212 • No evidence for Y(4260)   • 4 quark state [cs][cs]?Phys. Rev. D72 (2005) 031502 • Should decay dominantly to DsDs • Hybrid meson? • DD, D*D*, DD* decays suppressed • DD1(2420) decays should dominate • c1molecule?Phys. Lett. B634 (2006) 399 • hybrid + quenched lattice QCD predicts, for 1-- • M = 4380 ± 150 MeV/c2Phys. Rev. D74 (2006) 034502

  21. CC Summary • Possibly charmonium states • X(3940) = c(3S)?Y(3940) = ’c1? Z(3930) = ’c2? • Probably NOT charmonium states (what are they?) • X(3872), Y(4260), Y(“4325”) Y(4260) Y(3940) = ’c1? X(3940) = c(3S)? Z(3930) = ’c2? X(3872)

  22. NEXT The Status of Charmed Baryons

  23. Baryons with 4 flavors (u,d,s,c) 444 = 4 20’20’20 1/2+ 3/2+ Ground states * u,d,s, octet Anti-symmetric Ground state 1/2- u,d,s, decuplet All 9 ground states c=1, JP = ½ + observed 5 ground states with JP = 3/2 observed: only c* was missing

  24. The singly charmed u,d,c sub-multiplets from the 20’  9 members; JP = 1/2 e+e-  cc Charm baryon + X 3 (2285) 6 e+e-  BB (2472) (2574) (2466) (2579) (2698) About charmed baryons Anti-symm under the interchange of the two light quarks (u,d,s) symm. under the interchange of the two light quarks (u,d,s) Charmed baryons can be produced from continuum or from B-decays Characteristics: momentum of charmed baryon in e+e- rest frame, p*: high when produced in cc, low when produced in B decays

  25. Belle Babar Cleo c(2800) Charmed Baryon States Most of the JP’s assigned none measured

  26. Observation of Λc(2880)+ and Λc(2940)+ decaying to D0p BaBar PRL 98:012001(2007) Λc(2940) New Decay mode: Λc(2880)+ D0p First observation of charm baryon  charm meson Λc(2880) Nsig=2280310 Belle confirms in c  (c) Belle Hep-ex/0608043 Λc(2765) Λc(2880) Wrong sign D0P Λc(2940) D0p invariant mass GeV/c2 D0 mass sidebands M(ΛC + -) GeV/c2 Excellent agreement in mass and width

  27. Observation of c(2815) & c(2980) 414 fb-1 preliminary hep-ex/0608012

  28. New charm strange baryons BaBar confirms these states cx(3077)+ cx(2970)+ Belle, PRL97:162001(2006) BaBar hep-ex/0607042 preliminary

  29. c0Production and Decay c0 Decay PDG values hep-ex/0703030, submitted to PRL

  30. c0Production in B decays hep-ex/0703030, submitted to PRL From B decays:first observation Continuum production p* distribution, momentum in the e+e- rest frame Off-peak data: Below B-pair thres-hold, no peak

  31. BaBar PRL 231 fb-1 97:232001(2006) Discovery of the C* Data from all four c0 decay modes are combined and fit yields: 105  21  6 5.2 signal significance No signal found in the c0 mass Sidebands (hatched area) m ( mc* - mc0)= (70.8  1.0  1.1) MeV/c2 Theory range: m = 50 – 94 MeV/c2 = 1.01 0.23 0.11 Combined For XP > 0.5, most/all the c0 might result from c* production, but uncertainty is large.

  32. Also observed the charged partner c’+

  33. Measurement of Absolute Branching Fraction of c

  34. Measurement of B  cp

  35. Study of b → ccs decay BABAR, PRL. 95 142003, 2005 PRD 75 012003, 2007 Inconsistency in the MC and data p* distribution: MC only has b → cud Search B decays into charm-baryon-anti-charm-baryon pair B → cc and B → c c K

  36. B decays to cc and c cK Anexample E = energy difference between reconstructed B and Ecm mES : beam momentum substituted reconstructed B mass: e+e- BB

  37. B decays to cc PRD 74 (2006) 111105

  38. B decays to c cK PRL 97 (2006) 202003

  39. NEXT Spin Measurements

  40. L K+ (p+) W- Xc0 = 0 (Wc0 = 0) W- = 0 K- Examine implications of W- spin hypotheses for angular distribution of L from W- decay λ(L) = ± 1/2 q quantization axis λ(K) = 0 J = 1/2 m = + 1/2 m = - 1/2 λ(K) = 0  l(W) = + 1/2 l(W) = - 1/2 W- inherits the spin projections of the Xc0 since, no orbital angular momentum projection w.r.t. quantization axis in Ξc0 decay • Initial helicity,λi = λ(W)= ± 1/2 • Final state helicity, λf = λ(L) - λ(pseudoscalar) = ± 1/2 • Decay amplitude for Ω- → Λ K-:

  41. Spin measurement ofW-fromXc0 → W- K+, W- → L K- decays Data ~ 116 fb-1 Background-Subtracted Efficiency-Corrected PRL 97 (2006) 112001 Similar conclusion fromWc0 → W-p+, W- → LK-decays Conclusion:J(W-) = 3/2 [assumingJ(Xc0) = 1/2] JW = 1/2 → Fit Prob = 10-17 JW = 3/2 → Fit Prob = 0.64 → Fit Prob = 10-7 JW = 5/2

  42. Study ofX (1530)0and X (1690)0 Extending the Spin Formalism to 3-body Decays • The X(1530)0 Spin from Lc+→ (X-p+)K+ also mass, width info.  amplitude analysis (in progress) The X(1690)0 Spin from Lc+→ (L0KS0)K+ also mass, width info.  amplitude analysis (to be done)  (X-p+)/(LK0) Branching Ratio Limit (to be done) 12

  43. NEXT D0 – D0 Mixing

  44. Time-Evolution of D0 Decays D0 can reach the K+ - final state in two ways: 1) Doubly-Cabibbo-Suppressed decay 2) Mixing to D0bar, followed by Cabibbo-Favoured decay ... and interference between them. Q: How can we distinguish these? A: By the time evolution.

  45. Summary PDG 2006 95% CL allowed • Mixing contours from 2006 PDG • Kp decay the dominant mode in the search for mixing • CP lifetimes sensitive to measuring y • Semileptonic sensitive to RM= (x2+y2)/2 CPV allowed yCP=(0.900.42)% K=0 assumed dKp~ 0: measured by CLEO

  46. hep-ex/0703036 Submitted To PRL(Belle) hep-ex/0703020 Submitted To PRL (BaBar) 0704.1000v1 [hep-ex], Moriond EW/QCD 2007(Belle) Summary Updated with new results for this talk (HFAG plots will be available soon) • Assuming CP conservation BaBar has found evidence for mixing at 3.9s CL using D0Kp decay mode (384 fb-1) • ycp by Belle also evidence for mixing at 3.2sCL (540 fb-1) • Clear Evidence of Mixing • Most sensitive measurement of x by Belle(D0Kspp) • A precision measurement of cosdneeded to express mixing in x and y • CLEO-c quantum correlation • BaBar and Belle B-factories • Are also charm factories • Searches for CP violation • Improved techniques • More data 95% CL allowed CPV allowed Belle ycp (1s) Belle ycp BaBar Kp Belle Kspp K=0 assumed dKp~ 0: measured by CLEO

  47. Some Recent Theoretical Work • D-Dbar Mixing And New Physics: General Considerations and Constraints on the MSSN (M. Ciuchini et al) • hep-ph/0703204v1 • Lessons from BaBar and Belle measurements of D0-D0bar mixing parameters, (Y. Nir) • hep-ph/0703235v1 • Littlest Higgs Model with T-Parity Confronting the New Data on D0-D0bar Mixing,(M. Blanke et al) • hep-ph/0703254v1 • Basics of D0-D0bar Mixing, (P. Ball) • hep-ph/0703245v1

  48. Summary Experimental status: • A new landscape in many areas including spectroscopy has opened up with high luminosity and precision • New DsJ Spectroscopy • X, Y, Z States • Charmed Baryon Spectroscopy • Spin Measurements (necessary to identify levels, complex analysis for multi-body states: c (1530), c (1690), in Charmed Baryon decays ) • Evidence for D0-D0 Mixing • Lots of on-going analyses with the current dataset • More decay modes investigated to understand these resonances • Lots of new data to analyse! Expecting ~three/four times more data than shown in analyses A race to find Beyond Standard Model Physics

  49. Example: Mixing One of the main HEP discoveries in 2006: Bs Oscillations Bs0 oscillate very rapidly x=24.8 y~0.1? Rate first measured in 2006 by CDF and D0 Toy MC