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Non-standard mesons in BES III?

Non-standard mesons in BES III?. Stephen L. Olsen, Univ of Hawai’i BES annual mtg Shi-dou, May 30-June 2, 2005. non-standard hadrons. non-qqq baryons or non-qq mesons: Pentaquarks: e.g. an S=+1 baryon Glueballs: gluon-gluon color singlet states Multi-quark mesons:

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Non-standard mesons in BES III?

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  1. Non-standard mesons in BES III? Stephen L. Olsen, Univ of Hawai’i BES annual mtg Shi-dou, May 30-June 2, 2005

  2. non-standard hadrons non-qqq baryons or non-qq mesons: Pentaquarks: e.g. an S=+1 baryon Glueballs: gluon-gluon color singlet states Multi-quark mesons: qq-gluon hybrid mesons d u u d s u c u c c c

  3. mesons with “hidden charm” are a good place to look u c c c u c • standard cc mesons are: • best understood theoretically • decay properties well known • narrow & non overlapping • concentrate on charmonium-like particles that don’t match expected properties

  4. What about the y(4.03) ?Conventional wisdom: y(4.03)= y(3S) D*D* DD DD* Ecm(GeV/c)

  5. D momentum spectra @ 4.03GeV DD* DD* D*D* Ling-jun Pan, BES data DD D*D* DD D+ D0 Why is G(y(4.03) D*D*) so huge? DD/DD*/D*D*: 1/20/64 phase-space Charmonium S-wave: 1/4/7 removed D-wave: 1/1/4

  6. Suggestions y(4.03)=D*D* molecule? c c D* PRL 38, 317 p,s D* u u a cc-gluon hybrid? PLB 366, 323 c c

  7. hadronic moleculesa new spectroscopy?

  8. DeRujula, Georgi,Glashow, PRL 38, 317 (1977) Many possibilities For BESIII

  9. cc-gluon hybridsanother new spectroscopy?

  10. Hybrid states “normal” cc mesons 1–- hybrid mixes with y(4.03)?? DD cc gluon hybrids More possibilities For BESIII

  11. Belle has candidates for each • DD* molecular state: X(3872) • S.-K. Choi et al PRL 91, 262001 • cc-gluon hybrid: Y(3940) • S.-K/ Choi et al, PRL 94, 182882

  12. The X(3872) seen in: C=+ XgJ/y Xp+p-p0J/y Xp+p-J/y y’ X(3872) M(p+p-p0) MeV M(gJ/y) M(ppJ/y) –M(J/y) Ispin is violated & XD0D0p0 M(D0D0p0) MeV

  13. X(3872) = D0D*0 bound state? • JPC = 1++ (favored by DD* models) • M ≈ mD0 + mD0* • Maximal isospin violation is natural (& was predicted): |I=1; Iz= 0> =1/2(|D+D*->+ |D0D*0>) |I=0; Iz= 0> =1/2(|D+D*-> - |D0D*0>)  |D0D*0> = 1/2(|10> - |00>) • G(XgJ/y) < G(XppJ/y) Tornqvist PLB 590, 209 (2004) Equal mixture of I=1 & I =0 Swanson PLB 588, 189 (2004) Swanson PLB 598, 197 (2004)

  14. X(3872) conclusionsee hep-ex/0505037 & 0505038 • JPC = 1++ • cc content is small • matches all(?) expectations for a D0D*0 bound state C C c c D* p,s D* u u

  15. BES has a candidate too!from Ling-Jun’s y(4.03)  DX study Study this

  16. Look at DD* region D*+D+p0 D*+D+p0 D*+D+g D*+D+p+ D*0D0p0 D*0D0g

  17. Fits to momentum spectra are poor D* Br’s fixed at PDG values c2/dof = 129/78 CL:0.028% D+ Too few daughters D0 L.J. Pan, PhD thesis

  18. Addsome y(4.03)pŨ; ŨDD c2/dof = 100/73 CL: 5% Bry?p=16% ŨDD MŨ~3860 MeV GŨ<12 MeV ŨDD L.J. Pan, PhD thesis

  19. DeRujula, Georgi,Glashow, PRL 38, 317 (1977) Ũ(3860) X(3872)?? ŨDD allowed

  20. cc gluon candidate from Belle: Y(3940) BK wJ/y “Y(3940)” M≈3940 ± 11 MeV G≈ 92 ± 24 MeV Mbc Mbc Mbc Bf(BKY)Bf(YwJ/y)=7.1±1.3±3.1x10-5 S.K. Choi et al, PRL 94, 182882

  21. Y(3940): What is it? Brambilla et al (QWG) hep-ph/0412158 Eichten, Lane & Quigg PRD 64, 094019 Barnes, Godfrey & Swanson hep-ph/0505002 • Charmonium? • Conventional wisdom: wJ/y should not be a discovery mode for a cc state with mass above DD & DD* threshold! • Some kind of w-J/y threshold interaction? • the J/y is not surrounded by brown muck; can it act like an ordinary hadron? w J/y

  22. Y(3940): What is it (cont’d)? c • another 4-quark state? • M ≈ 2mDs • not seen in YhJ/y • (h contains ss) • width too large?? • no p exchange for DSDS s s c ?? PRL 93, 041801 M(h J/y)

  23. Y(3940): What is it (cont’d) ? • cc-gluon hybrid? • predicted by QCD, • decays to DD and DD* are suppressed (“open-charm” thresh = mD + m D** = 4.3 GeV) • large hadron+J/y widths are predicted • masses expected to be 4.3 ~ 4.4 GeV (higher than what we see) Horn & Mandula PRD 17 898 (1978) Isgur et al PRL 54, 869 (1995) Close PLB 342, 369 McNiele et al PRD 65 094505 c c

  24. “open charm” threshold for hybrids is here DD* D*D* DD Ecm(GeV/c) Hybrid states in this mass range may decay to x J/y (or hc, cc,…) x=light hadrons

  25. Search strategies for BESIII • DD(*) molecular states • y(4.03)p(g) + Ũ • Study DD & DD* masses @ y(4.03) (& y(4.16)??) • light cc gluon hybrids • y(4.03) g + ccg hybrid • Study J/y (cc, hc) + light hadons (g) @ y(4030), y(4160) (& y(4415)??)

  26. Rate estimates (DD(*) molecules)(1yr = 6fb-1) • L.-J. Pan’s thesis: ~16% of y(4.03)DDp yield is via: y(4.03)p Ũ(3860) DD If DD recon effic ~0.1% Expect: 103 Ũ(3860)DD/yr including D Br’s

  27. Rate estimates (cc-gluon hybrids) or gg,orp • y(4.03) g + (cc gluon hybrid) • assume: G(y(4.03)g wJ/y)~G(y(3.77)ppJ/y)~100keV Recon effic wJ/y ~ 1% G(y(4.03)gwJ/y) G(y(3.77)ppJ/y) N(y(4.03)gwJ/y) ~ 103/yr x Can search in many other channels: y(4.03)g (gg,p) + ppJ/y ( hJ/y, ppcc, …)

  28. Summary BESIII runs at 4.03 (& 4.16 GeV + higher?) may be very interesting.

  29. 謝謝

  30. Announcement

  31. 謝謝

  32. Backup slides

  33. Look at events where 2 D mesons are found ???? Expect ~ 10 ??(3860)DD events L.J. Pan, PhD thesis

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