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Test of pQCD 12% Rule at BES

Test of pQCD 12% Rule at BES. Yongsheng ZHU IHEP, Beijing 100039, China for the BES Collaboration. 32 nd Intern. Conf. on High Energy Physics ( ICHEP’04 ) Aug. 16-22, Beijing, China. OUTLINE Introduction (2S)  VP (,,)(,,’),K*K

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Test of pQCD 12% Rule at BES

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  1. Test of pQCD 12% Rule at BES Yongsheng ZHU IHEP, Beijing 100039, China for the BES Collaboration 32nd Intern. Conf. on High Energy Physics ( ICHEP’04 ) Aug. 16-22, Beijing, China

  2. OUTLINE • Introduction • (2S)  VP (,,)(,,’),K*K • (2S)  VT f2,a2,K*K*2, f2' • J/, (2S)  PP KSKL • Summary

  3. INTRODUCTION World J/ and (2S) Samples (×106) J/ (2S) 14M 14M 58M 3M

  4. INTRODUCTION (Con’t) pQCD 12% rule : T. Appelquist & H.D. Politzer, PRL 34 (1975) 43 • A. De Rujula & S.L. Glashow, PRL 34 (1975) 46 • J/ and ’ hadronic decays proceed via 3 gluons or • a virtual photon, • omitting the difference of S at J/ and ’ , • the ratio of ’ and J/ BRs is • Assumption : • This relation holds for any exclusive hadronic final state.

  5. INTRODUCTION (Con’t)  puzzle: • Suppression in VP mode ( & K*K ) revealed by MARK-II • { M.E.B. Franklin et al, PRL 51 (1983) 963 } • Suppression confirmed by BESI with higher sensetivity • { Y.S.Zhu, Proc. of ichep ‘96, p.507 } • Suppression in VT mode found by BESI • { J.Z.Bai et al, PRL 81 (1998) 5080 } • Q(f2) < 4.0%, Q(a2)< 2.1%, Q(K*K*2) < 1.8%, Q(f2’) < 3.7%

  6. INTRODUCTION (Con’t) • Theoretical explanations: • Brodsky, Lepage, Tuan:{ PRL 59 (1987) 621 } • Intermediate vector glueball • Chaichian & Torngvist :{ NP B323 (1989) 75 } • Hadronic form factor • Pinsky :{ PL B236 (1990) 479 } • Generalized hindered M1 transition • Li-Bugg-Zou{ PR D55 (1997) 1421 } • Final-state interaction • Brodsky-Karliner{ PRL 78 (1997) 4682 } • Intrinsic charm |qqcc> Fock components of the light vector mesons • Chen-Braaten { PRL 80 (1998) 5060 } Fock state with cc pair in a color-octet

  7. INTRODUCTION (Con’t) • Theoretical explanations: • Gerard-Weyers { PL B462 (1999) 324 } • cc annihilation into 5g via 2 steps • Feldmann-Kroll { PR D62 (2000) 074006 } • Decays thru light-quark Fock component by a soft mechanism • Suzuki { PR D63 (2001) 054021 } • (2S) - vector glueball mixing • Rosner { PR D64 (2001) 094002 } • (2S) - (1D) mixing • J. P. Ma { PR D65 (2002) 097506 } • Relativistic Correction

  8. The phase and interference in e+e – experiment φ Phase interference interference • For decays via strong and EM amplitudes, • the phase and continuum contribution must be considered. • For EM decays, • the continuum contribution must be considered.

  9. INTRODUCTION (Con’t) • Measure the BRs of(2S) & corresponding • Q values • for 10VP channels, • 4VT channels, • 1PP channel, • to test pQCD 12% rule.

  10. 1. VP Mode • BRs for (2S)(,,)(,,’),K*K measured • PWA for (2S)+  - 0 • Background from continuum considered using Ecm=3.65 GeV data sample

  11. 1. VP Mode (Con’t) 1.1  hep-ex/0408047 submitted to PRL Dalitz plot for J/ Ψand Ψ(2S)3 are very different J/ Ψ 3 Ψ(2S) 3 PRD70 (2004) 012005 BESII Preliminary

  12. 1. VP Mode (Con’t) M in Ψ(2S) 3 (770), (2150) -- dominant BESII Preliminary ( PWA ) 1.1 

  13. 1. VP Mode (Con’t) BESII Preliminary ( PWA ) 1.1  (Con’t) Results on BRs ____________________________________________________________________________________________________________________________________________ BR BESII (10 – 5 ) PDG04 (10 – 5 ) Ψ(2S) + -0 18.1  1.8  1.9 8  5 Ψ(2S) 5.1  0.7  0.8 < 8.3 Ψ(2S)  (2150) + -0 19.4  2.5 ____________________________________________________________________________________________________________________________________________ # 1st measurement or precision much improved # Interference taken into account

  14. 1. VP Mode (Con’t) Dalits plot in  (2S) KSK K*(892)K 1.2 K*(892)K K* K* K*0 K*0 hep-ex/0407037 , submitted to PRL

  15. 1. VP Mode (Con’t) Br0(15.0±2.1±1.9)10 –5 Br±(2.9±1.3±0.4)10 –5 1.2 K*(892)K(Con’t) Ψ(2S) K 0 Ψ(2S) K + K*0 K* 9.6±4.2 Evts. 65.6±9.0 Evts. =5.2±2.7 isospin-violation

  16. 1.3 EM Process:0,,’ at Ecm=3650,3686,3773 MeV 1. VP Mode (Con’t) # For EM processes at continuum e+e- (VP) 0 , , ’ Pvp(S)=q3vp/3; q3vp – momentum of V or P ; Fvp(s) – form factor ; =1, 0.672, 0.325 for 0 ,, ’ . # For EM processes at Ψ(2S) (VP) 0, , ’ =R+cont(INT  0, P.Wang et al, PL B593 (2004) 89 ) #BRs & Fvp(M Ψ(2S)) obtained simultaneously interference

  17. 1. VP Mode 1.3 EM Process:0,,’ at Ecm=3650,3686,3773 MeV BESII Preliminary e+e- 0 at Ecm=3686 MeV N Ψ(2S) = 14M e+e- 0 at Ecm=3650 MeV L = 6.42 pb-1 e+e- 0 at Ecm=3773 MeV L = 17.3 pb-1

  18. 1.3 EM Process:0,,’ at Ecm=3650,3686,3773 MeV FVP(S) and B(Ψ(2S) VP) for 0,,’ BESII Preliminary

  19. 1.3 EM Process:0,,’ at Ecm=3650,3686,3773 MeV BESII Preliminary Form factor for Ψ(2S) 0 Curve A -- J.Gerard, PLB425(1998)365 F(0) ~ 1/S Curve B –V.Chernyak, hep-ph/9906387 F(0) ~ 1/S2

  20. 1.4 Results of VP mode Upper limit @90％ C.L. * Preliminary

  21. BESII Preliminary BESII vs. CLEO (’ BRs Results) Upper limit @90％ C.L. • Most channels • BRs are • consistent. • BES BR() • > CLEO • by ~ 3, • because PWA • takes into • acount the • interference. • BR(K*0K0) are • deviated CLEO BRs calculated from hep-ex/0407028

  22. 2. VT Mode • BES-I results PRL81(1998)5080 PRD67(2003)052002 † This value from DM2 only Suppressed!! 12 % rule ( pQCD rule ) Test

  23. 2. VT Mode (Con’t) BES-II † This value from DM2 only Suppressed!! PR D69 (2004) 072001

  24. 3. PP Mode PRL92 (2004) 052001 PRD69 (2004) 012003 Ψ(2S) KS KL J/Ψ  KS KL 14M ψ(2S) 58M J/ψ Bkg MC signal signal MC Bkg K*0KS+c.c. Ks mass sidebands Ks mass sidebands

  25. 3. PP Mode(Con’t) B(2S) Ks K L= (5.24± 0.47± 0.48 )  10 – 5 1st measurement Improved Accuracy BJ/ Ks K L = (1.82 ± 0.04± 0.13 )  10 – 4 B(Ψ(2S)) enhanced!

  26. 3. PP Mode(Con’t) Phase between strong and EMamplitude Ψ(2S)  KS KL B( (2S) KS KL ) = 5.2410 – 5 K+K– & +  inputs ; Input 1:DASP; Input 2:BESI ; Input 3: K+K– from BESI & + by form factor. PLB567 (2003)73 –(8229)° (12127)°

  27. SUMMARY # Measurementsfor BRs or upper limits of VP channels: ’(,,)(,,’), K*K # In ’ 3,(770) & (2150)dominant. # Large isospin-violation in ’ KK* channel. # F(0,,’) at Ecm=3650, 3686, 3773 MeV measured. # Improved BRs of VT channel ’f2, a2, K* K*2, f2’ # First measurementfor BR of Ψ(2S)  KS KL ; Phase between EM and strong amplitudes is -82o or 121o. #12% rule tested for all these decay modes. somesuppressed, some enhanced, some consistent.

  28. Test of pQCD 12% Rule SUMMARY BESII Preliminary

  29. Test of pQCD 12% Rule SUMMARY BESII preliminary

  30. Comments # 12% rule seems to be too simplistic. # A theory which can quantitatively describing these data is desired. # More and accurate data on J/ and (2S) are helpful to elucidate the J/ and (2S) properties, as well as properties of strong interaction.

  31. Thanks a lot ! 谢谢!

  32. INTRODUCTION BESII Detector VC: xy = 100 m TOF: T = 180 ps  counter: r= 3 cm MDC: xy = 220 m BSC: E/E= 22 % z = 5.5 cm dE/dx= 8.5 %  = 7.9 mr B field: 0.4 T p/p=1.7(1+p2) z = 2.3 cm

  33. INTRODUCTION (Con’t) 1. ψ(2S) 2. Other quarkonia 3. Hadron spectroscopy

  34. 1. VP Mode (Con’t) 1.2 K*(892)K(Con’t) BRs of  & K+K* -- +ccComparison with previous results (Upper limit @90％ C.L.) * Y.S.Zhu, Proc. Ichep 96, p.507 **BES II . PWA takes into account (770), excited  states & their interferencies.

  35. 1. VP Mode (Con’t) BESII Preliminary ( PWA ) 1.1  (Con’t)

  36. 1.3 EM Process:0,,’ at Ecm=3650,3686,3773 MeV BESII Preliminary e+e-  at Ecm=3650MeV e+e-  at Ecm=3773 MeV Ψ(2S)  e+e- ’ at Ecm=3650MeV e+e- ’ at Ecm=3773 MeV Ψ(2S) ’

  37. 1.4 Other VP Channels BESII Preliminary Ψ(2S)  { Ψ(2S)  0 not seen } Ψ(2S) ’ ( ’+-, +- )

  38. BESII Preliminary BESII vs. CLEO (’ BRs Results) Upper limit @90％ C.L. • Most channels • BRs are • consistent. • BES BR() • > CLEO • by ~ 3, • because PWA • takes into • acount the • interference. • BR(K*0K0) are • deviated. CLEO BRs calculated from hep-ex/0407028

  39. 2. VT Mode BES-II B.G.(  ) a2 (1320) f2 (1270) B.G. B.G.(M.C.) f0(980) K*(892) f2'(1525) B.G. K*2 (1430) B.G.

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