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New Spectroscopy of Heavy Mesons

New Spectroscopy of Heavy Mesons. Fulvia De Fazio INFN - Bari. How to ( try to ) understand the properties of recently discovered states using the heavy quark limit. Collaborators : P. Colangelo , R. Ferrandes , S. Nicotri , A. Ozpineci , M. Rizzi. Open charm/beauty states.

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New Spectroscopy of Heavy Mesons

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  1. New SpectroscopyofHeavyMesons Fulvia De Fazio INFN - Bari Howto (tryto) understand the propertiesofrecentlydiscoveredstates using the heavy quark limit Collaborators: P. Colangelo, R. Ferrandes, S. Nicotri, A. Ozpineci, M. Rizzi F. De Fazio INFN Bari

  2. Open charm/beauty states • D0(2308), D’1(2440) • Ds0*(2317), D’s1(2460) • D(2550), D(2600), D(2750), D(2760) • DsJ(2632) • DsJ(2860), DsJ(2710), DsJ(3040) • B1(5734), B*2(5738) • Bs1(5830), B*s2(5840) F. De Fazio INFN Bari

  3. Open charm/beauty states • D0(2308), D’1(2440) • Ds0*(2317), D’s1(2460) • D(2550), D(2600), D(2750), D(2760) • DsJ(2632) • DsJ(2860), DsJ(2710), DsJ(3040) • B1(5734), B*2(5738) • Bs1(5830), B*s2(5840) Seenonlyby SELEX, neverconfirmed F. De Fazio INFN Bari

  4. Open charm/beauty states • D0(2308), D’1(2440) • Ds0*(2317), D’s1(2460) • D(2550), D(2600), D(2750), D(2760) • DsJ(2632) • DsJ(2860), DsJ(2710), DsJ(3040) • B1(5734), B*2(5738) • Bs1(5830), B*s2(5840) Seenonlyby SELEX, neverconfirmed F. De Fazio INFN Bari

  5. Hadronscontaining a single heavy quark Q Spinof the heavy quark and of the light degreesoffreedom decoupled in the mQ→ ∞limit Spinsymmetry angularmomentum of the light degreesoffreedom (conserved) spin Mesonsclassifiedasdoublets the membersofwhichhave The heavy quark flavourbecomesirrelevantasmQ→ ∞ possibilitytorelate charm and beauty hadronproperties Flavoursymmetry F. De Fazio INFN Bari

  6. HQ limitformesondoublets and strong decaysto light pseudoscalars The twostateswithin a givendoublet are degenerate Theyhave the same total width The sum of the partialwidthsof a state in a doubletto a state in anotherdoublet withemissionof a light mesonis the samefor the twostatesof a doublet Spinsymmetrypredicts the ratiosofpartialdecaywidthsfor a given state Partialdecaywidths are independent on the HQ flavour Mass splittingsamong the doublets are independentof the HQ flavour Spin symmetry Flavour symmetry F. De Fazio INFN Bari

  7. Qqmultiplets D-wavedoublets: (D’(s)2,D(s)3), (B’(s)2,B(s)3) (D*(s)1,D(s)2), (B*(s)1,B(s)2) P-wavedoublets: (D(s)1,D*(s)2), (B(s)1,B*(s)2) (D*(s)0,D’(s)1), (B*(s)0,B’(s)1) fundamentaldoublet: (D(s),D*(s)), (B(s),B*(s)) F. De Fazio INFN Bari

  8. Qqmultiplets Strong transitionsbetweenmultiplets + pseudoscalar meson d-wave transition mesons are expectedtobenarrow + pseudoscalarmeson s-wave transition mesons are expected to be broad F. De Fazio INFN Bari

  9. cqmultiplets Low lyingRad. Excitations F. De Fazio INFN Bari

  10. csmultiplets Low lying F. De Fazio INFN Bari

  11. csmultiplets Low lying D*K threshold D K threshold F. De Fazio INFN Bari

  12. DsJ(2860) • DiscoveredbyBaBarCollab. • Reconstructed in • and in BaBar Collab., PRL 97 (06) 222001 Quantum numberassignmentrequired in ordertoidentifyit Possibilities: - low lying state notyetobserved - radialexcitationofanalreadyobserved state Onlystatesthat can decayto the observed mode DK are allowed F. De Fazio INFN Bari

  13. csmultiplets Low lyingRadexcitations F. De Fazio INFN Bari

  14. csmultiplets Low lyingRadexcitations forbidden forbidden forbidden forbidden forbidden F. De Fazio INFN Bari

  15. csmultiplets Low lyingRadexcitations allowed forbidden forbidden allowed allowed forbidden forbidden allowed allowed forbidden F. De Fazio INFN Bari

  16. DsJ(2710) Belle Collab.: analysisof the mode New resonance decaying to D0K+ with: implies P=-1 J=0 J=1 J=2 JP=1-favoured A broadstructure at M=2688 MeVwithG=112 MeV wasfoundbyBaBar in the DK mass distribution F. De Fazio INFN Bari

  17. csmultiplets Low lyingRadexcitations F. De Fazio INFN Bari

  18. csmultiplets Low lyingRadexcitations F. De Fazio INFN Bari

  19. DsJ(2860) & DsJ(2710) predictions on alloweddecayrates can help todistinguishamong the variouspossibilities HQ limit: the membersof the doublets are describedbyeffectivefields: L=0 L=1 L=2 F. De Fazio INFN Bari

  20. DsJ(2860) & DsJ(2710) Interactionswith the emissionof a light pseudoscalarmesondescribedbyeffectiveLagrangianterms H H p S H p T H p X H p X’ H p Analogoustermsdescribeinteractionsinvolvingradialexcitationdoublets: F. De Fazio INFN Bari

  21. DsJ(2860) : resultsforwidthratios P. Colangelo, S. Nicotri, FDF PLB 642, 48 1 2 3 4 5 Would explain the observed narrowness F. De Fazio INFN Bari

  22. DsJ(2860) Oursupportedoption: 5 • Signalexpected in D*K • Smallsignalexpectedalso in Ds  In this case the smallwidth can beattributedto the suppression due to the kaonmomentumfactor: f-wave transition Assuming the experimentally measured width would predict in the typical range of these couplings The spin 2 partner coulddecay in p-wave due to the effectof 1/mQcorrections mayescape detection Ourconclusion: DsJ(2860) is likely to be a JP=3- state ShoulddecaytoD*K F. De Fazio INFN Bari

  23. IdentifyingDsJ(2710) throughitsdecaymodes P. Colangelo, S. Nicotri, M. Rizzi, FDF Phys. Rev. D77, 014012 the dependence on the (unknown) couplings drops out The D*K decay is the signal that must be investigated in order to distinguish the two possible assignments F. De Fazio INFN Bari

  24. BaBarAnalysisofD*Kfinalstates • D*Kinvariant mass spectrum • (background-subtracted) • angularanalysis Three peaks are visible: The angulardistributionisconsistentwith the expectationsforstateswithnaturalparity (0+,1-,2+,3-,…) for Ds1(2710) and DsJ(2860) BaBar, PRD80 (09 )092003 excludedby the observation of the D*K mode F. De Fazio INFN Bari

  25. BaBarAnalysisofD*Kfinalstates • D*Kinvariant mass spectrum • (background-subtracted) • angularanalysis Three peaks are visible: The angulardistributionisconsistentwith the expectationsforstateswithnaturalparity (0+,1-,2+,3-,…) for Ds1(2710) and DsJ(2860) BaBar, PRD80 (09 )092003 excludedby the observation of the D*K mode tobediscussedlater… F. De Fazio INFN Bari

  26. BaBarAnalysisofD*Kfinalstates Branching fractions Supports the identification of Ds1(2710) with 23S1 (first radial excitation of Ds*) Does not support or discard unambiguously any interpretation: still to be understood F. De Fazio INFN Bari

  27. csmultiplets Low lyingRadexcitations F. De Fazio INFN Bari

  28. csmultiplets Low lyingRadexcitations F. De Fazio INFN Bari

  29. cqmesons BaBarobservesfournewstateswith charm and withoutstrangeness: BaBar, PRD 82 (10) 111101 F. De Fazio INFN Bari

  30. cqmesons Studyof the distribution in the helicity angle qHfor the final state D*p BaBar, PRD 82 (10) 111101 Angle between the primaryp and the slow pfromD*decay Godfrey & Isgur (85) • Consistentwithassignementsof • NaturalparityforD*(2600) • JP=0+for D(2550) • Comparisonwithpotentialmodel • Seemsto indicate that • (D(2750),D*(2760)) are L=2 states F. De Fazio INFN Bari

  31. cqmesons BaBarobservesfournewstateswith charm and withoutstrangeness: BaBar, PRD 82 (10) 111101 likelytobe the radialexcitationsof (D,D*) likelytobe L=2 states F. De Fazio INFN Bari

  32. cqmultiplets Low lyingRad. Excitations F. De Fazio INFN Bari

  33. cqmesons BaBar, PRD 82 (10) 111101 Experimentalratios: Theseratiostogetherwithmasses and widths can beusedtocheck the BaBarassignments F. De Fazio INFN Bari

  34. cqmesons Branching fractionRatio IdentifyingD*(2600) with the first radialexcitationof D*0 weobtain: whileBaBarfinds: P. Colangelo & FDF, in preparation F. De Fazio INFN Bari

  35. cqmultiplets: whichstates can decaybothtoDp and D*p? Low lyingRad. Excitations F. De Fazio INFN Bari

  36. cqmultiplets: whichstates can decaybothtoDp and D*p? Branching fractionratiosfor the otherthreepossibilities:vs the mass of the decayingmeson No assignmentto a mesonof mass 2600 MeV wouldreproduce the expresult: Either HQ symmetryisstronglyviolated or a revisionof the experimentalanalysis isrequired F. De Fazio INFN Bari

  37. DsJ(3040) The onlyadditional information isthatitdecays→ D*K YES → DK NO JP=1+, 2-, 3+,… F. De Fazio INFN Bari

  38. csmultiplets Low lyingRadexcitations F. De Fazio INFN Bari

  39. csmultiplets Low lyingRadexcitations F. De Fazio INFN Bari

  40. csmultiplets Low lyingRadexcitations wouldimplyan (unlikely) mass inversionifDsJ(2860) hasbeenproperlyplaced F. De Fazio INFN Bari

  41. DsJ(3040): howto discriminate among the fourpossibilities? • info fromRelativistic Quark Model (RQM) • Allowed strong decays: • - toD*(s) + light pseudoscalarmeson • D*K, D*s • - tomembersofhigherdoublets + a light pseudoscalarmeson • D*0K, D*s0 , D’1K • D1K, D*2K • - to D(s) + a light vectormeson • DK*, Ds F. De Fazio INFN Bari

  42. DsJ(3040): howto discriminate among the fourpossibilities? • decays in s-wavetoD*K, Ds* (broader), has the largest R1 , • the largestwidthto light vectormesons P. Colangelo , FDF PRD81, 094001 F. De Fazio INFN Bari

  43. DsJ(3040): howto discriminate among the fourpossibilities? • decays in s-wavetoD*K, Ds* (broader), has the largest R1 , • the largestwidthto light vectormesons P. Colangelo , FDF PRD81, 094001 • the two 2-statesshouldnotbeobserved in the decayto light vectormesons F. De Fazio INFN Bari

  44. DsJ(3040): howto discriminate among the fourpossibilities? • decays in s-wavetoD*K, Ds* (broader), has the largest R1 , • the largestwidthto light vectormesons P. Colangelo , FDF PRD81, 094001 • the two 2-statesshouldnotbeobserved in the decayto light vectormesons • Ds2 cannotdecayto D1K butshouldhave the largestwidthto D2*K F. De Fazio INFN Bari

  45. DsJ(3040): howto discriminate among the fourpossibilities? • decays in s-wavetoD*K, Ds* (broader), has the largest R1 , • the largestwidthto light vectormesons P. Colangelo , FDF PRD81, 094001 • the two 2-statesshouldnotbeobserved in the decayto light vectormesons • Ds2 cannotdecayto D1K butshouldhave the largestwidthto D2*K • look at the featuresof the spin partner F. De Fazio INFN Bari

  46. DsJ(3040): howto discriminate among the fourpossibilities? • decays in s-wavetoD*K, Ds* (broader), has the largest R1 , • the largestwidthto light vectormesons P. Colangelo , FDF PRD81, 094001 • the two 2-statesshouldnotbeobserved in the decayto light vectormesons • Ds2 cannotdecayto D1K butshouldhave the largestwidthto D2*K • look at the featuresof the spin partner F. De Fazio INFN Bari

  47. Concludingremarks • - all the observedcsstatesclassifiedasordinarymesons • DsJ(2700)identifiedwith D*’s • DJ(2600)mostlikelyits non strange partner: BR ratiotobereconsidered • Stilltobeunderstood: DsJ(2860) (JP = 3- ?) • DsJ(3040) variousalloweddecaymodesmay help in the classification • D(2750) and D(2760) : probably L=2 states F. De Fazio INFN Bari

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