Some Theoretical Issues of Hadron Productions and Properties from J/  Decays

1. Some Theoretical Issues of Hadron Productions and Properties from J/ Decays Shen Pengnian Institute of High Energy Physics(IHEP) Chinese Academy of Sciences shenpn@mail.ihep.ac.cn Aug.30-Sept.4,2004 MENU’04

2. Introduction • Baryon and its Excited States in J/ Decay • Multiquark Systems in J/, Decays • Remarks Collaborators: IHEP: H.C.Chiang, B.S.Zou, Z.Y.Zhang, R.G.Ping, W.H.Liang, F.K.Guo, Z.Q.Zeng, H.M.Zhao GSCAS: Y.B.Ding Nankai U.: X.Q.Li

3. Introduction Hadron: smallest directly observed particle • Structure - Meson - Baryon - Multiquark states

4. NPQCD models • Interaction: QCD theory - Potential model - Bag model - Lattice calculation - QCDSR, QFT ...

5. structure interaction Different interaction energy Spectrum Different Decay property Spectrum • experimental data of Decay property base of model theory • some unsolved problems - missing baryon excited state

6. Prog. Part. Nucl. Phys. 45 (2000) S241

7. - Roper resonance 3q? 3q-g? 5q? - Existence of multiquark states • Need further experimental and theoretical investigations

8. Baryon and its excited state studies in J/ decay • N*production via J/ decay W.H.Liang et al., J.Phys.G28(2002)333 B.S.Zou et al., Phys.Rev.C67(2003)015204

9. N*production processes • p N • electro- and photo-production • J/ hadronic decay

10. advantages of N* production through J/ decay • simple isospin structure • easily study N* that couples to • simultaneously study N*(3q) and N*(3q-g)

11. can study lower lying *, *, * • covariant tensor PWA for decay data analysis • effective vertices involved should satisfy • Lorentz invariant • CPT invariant • C invariant • P invariant

12. background analysis N-pole contribution W.H.Liang et al., nucl-th/0404024

13. in case • coupling vertex PS: • coupling vertex PV:

14. branching ratio for • experimental data: • calculated results: take |F0|/|FM|=0.12 PS: • without form factor PV:

15. with form factor frequently used form factors

17. branching ratio for

18. Take frequently used form factors [1] C.Schütz et al., Phys.Rev.C49(1994)2671 [2] B.C.Pearce et al., Nucl.Phys.A528(1991)655 [3]Y.Oh et al., Phys.Rev.C63(2001)25201 N-pole contribution is about 5~20% of data

19. for • experimental data • calculated result without F.F. with F.F. N-pole contribution is <1% of data

20. In case • NN coupling vertices vector tensor

21. branching ratio • calculated result ( ) without F.F. • experimental data with F.F. N-pole contribution is about 5~10% of data

22. application of J/ decay in baryon • model study W.H.Liang, Ph.D. thesis, (2002) • extract vertex information from RCQM decay amplitude in hilicity frame decay amplitude in covariant tensor analysis

25. extract vertex information from GBE Vertices in GBE

26. Vertices in covariant tensor analysis

29. calculation in 0 take and missing state 0 Cos() Cos() that strongly couple to N decay channel† into account RCQM GBE † vertex coupling parameters are extracted from S.Capstick et al.,Phys.Rev.D49(1994)4570 Phys.Rev.D46(1992)2864 †† vertex coupling parameters are extracted from D.O.Riska et al.,Nucl Phys.A663-664(2000)103

30. J/ Decay for Structure Study of Baryon • and its excited state R.G.Ping et al., Phys.Rev. D66(2002)054020, Chin.Phys.Lett.19(2002)1592,nucl-th/0408007 • some microscopic diagrams • assume • and can be treated by perturbative QCD • hadronization can approximately be considered by taking • quark model wave function of baryon

31. study using (uds) basis and considering Lorentz boost At least ground states of baryon can be well described by simply quark model

32. N*(1440) structure (w.f.) 3q: • study gI through and 3q-g: 3q- (3q-g):

33. Parameter setting

34. numerical results Further data distinguish structure of Roper

35. Possible Multiquark Systems in • J/, ’,Y decays • production way • direct production • dynamic production

36. 6q system? • experiment data of S-wave Breit-Wigner fit P-wave Breit-Wigner fit J.Z.Bai et al., BES Collaboration, Phys.Rev.Lett. 91(2003)022001

37. Some recent theoretical discussions • FSI ? • can be explained by interaction gained from LEAR • (B.Kerbikov et al., Phys.Rev.C69(2004)055205) • final state interaction: ( B.S.Zou,et al.,Phys.Rev.D69(2004)034004)

38. bound state or a resonant state ? • Toy model: ( D.Alakabha et al.,Phys.Lett.B567 (2003)273) • Skyrme model: ( M.L.Yan,et al.,hep-ph/0405087) • linear  model: ( X.Liu,et al.,hep-ph/0406118) • constituent quark model: ( C.H.Chang,et al.,hep-ph/0405087)

39. Paris potential: M.Pignone,et al.,Phys.Rev.C50(1994)2710 no S-wave bound state or resonant state Z.Q.Zeng et al.,manuscript no S-wave bound state or resonant state

40. experiment data of M.Ablikim et al., BES Collaboration, hep-ex/0405050 S-wave Breit-Wigner fit

41. Some recent theoretical discussions Symmetry analysis X.G.He et al., hep-ph/0407083 is possible a In or state

42. 5q system? • experimental data of and M.Ablikim et al., BES Collaboration, hep-ex/0402012 No significant (1540) signal

43. 4q system? • heavy quarkonium  transitions

44. suggest a new mechanism X mightbe a quark state This 4 quark state was also suggested by V. Anisovich et al., Phys.Rev.D51(1995)R4619 • further study on q-g degrees of freedom is needed

45. Conclusion • N* spectrum can provide information of baryon • inner structure and NPQCD effect of strong • interaction • J/ decay can produce N* for baryon spectrum • study • Possible to produce multiquark states via J/, ’, • Y decay, further study on q-q DOF is needed

46. Thank you