1. QM06 - S.H.Lee 1 1.Comments on J/  dissociation by partons 2.Progress in QCD calculations: LO and NLO 3. Dissociation due to thermal gluons and quarks J/  hadron interaction in vacuum and in QGP Su Houng Lee Yonsei Univ., Korea References: Y. Oh, S. Kim, S.H.Lee, (LO) : PRC 65 (2002) 067901 Taesoo Song, S.H.Lee, (NLO) : PRD 72 (2005) 034002 Y. Park, K. Kim, T. Song, K. Ohnishi, K. Morita S.H.Lee …

2. QM06 - S.H.Lee 2 1. 1986: Matsui and Satz J/  suppression 2.Nuclear and comover suppression 3.SPS data J/  suppression in Heavy Ion collision 4. Thermal enhancement 5. Lattice shows J/  survives up to 1.6 Tc (Asakawa, Hatsuda.. ) 6. Preliminary RHIC data SPS data RHIC data

3. QM06 - S.H.Lee 3 Relevant questions and steps in J/  suppression c c c c 1.c c are produced by hard collision 2.T initial > 300 MeV in RHIC 3.As systems cools, J/  is formed at 1.6 Tc 4.Dissociation effects until Tc ? 5.Suppression in hadronic phase …  Calculate J/  dissociation cross section by partons

4. QM06 - S.H.Lee 4 Progress in QCD calculations LO and NLO

5. QM06 - S.H.Lee 5 Basics in Heavy Quark system 1. Heavy quark propagation Perturbative treatment are possible because

6. QM06 - S.H.Lee 6 2. System with two heavy quarks Perturbative treatment are possible when

7. QM06 - S.H.Lee 7 q 2 process expansion parameter 0 Photo production of open charm -Q 2 < 0 QCD sum rules for heavy quarks m 2 J/  > 0 Dissociation cross section of bound states Perturbative treatment are possible when

8. QM06 - S.H.Lee 8 Quarkonium Hadron interaction in QCD - LO 1.Peskin (79), Bhanot and Peskin (79) 2.Kharzeev and Satz (94,96), Arleo et.al.(02,04) 3.Y.Oh, SHL (02) Rederived using Bethe-Salpeter amplitude (02) NR Power counting in Heavy bound state

9. QM06 - S.H.Lee 9 LO Amplitude

10. QM06 - S.H.Lee 10 Not so large, however, LO QCD result is known to underestimate nucleon absorption cross section s 1/2 (GeV) Exp data from pA Oh, Kim,SHL 02

11. QM06 - S.H.Lee 11 NLO Amplitude (Song, SHL 05)

12. QM06 - S.H.Lee 12 NLO Amplitude : 11 Collinear divergence when  1 =0. Cured by mass factroization

13. QM06 - S.H.Lee 13 Mass factorization 11 Gluons whose kcos  1 < Q scale, should be included in parton distribution function Integration of transverse momentum from zero to scale Q 11

14. QM06 - S.H.Lee 14 NLO Amplitude :

15. QM06 - S.H.Lee 15 Total cross section for Upsilon by nucleon: NLO vs LO Large higher order corrections Even larger correction for charmonium NLO/LO T. Song and SHL, PRD 72, 034002 (2006)

16. QM06 - S.H.Lee 16 1. Large NLO correction near threshold, due to log terms 2. But at finite temperature, thermal masses will regulate the large correction Thermal quark and gluon masses of 300 MeV will Reduce the large correction Lessons from NLO calculation

17. QM06 - S.H.Lee 17 Thermal width of J/  LO and NLO

18. QM06 - S.H.Lee 18 Assume cc bound state above T c 2. C. Y. Wong… : Deby screened potential  (GeV) 0 -0.8 Tc 1.6xTc J/  Binding energy as a function T J/  wave functions at finite T These will be used throughout this work But result is the same when is fixed

19. QM06 - S.H.Lee 19 LO  +g  c+c Increasing T

20. QM06 - S.H.Lee 20 NLO  +q  c+c+q Low T Hight T

21. QM06 - S.H.Lee 21 NLO  +g  c+c+g NLO 4 body decay ?

22. QM06 - S.H.Lee 22 Result and Summary 2. We showed that the process q(g)+J/   c+c+q(g) gives large thermal width (200 MeV) for J/  from 1.3 to 1.6 T c  this corresponds to about = 2-3 mb 3. In heavy ion collision, as the initial QGP cools down, J/  will start forming at 1.6 T c. However, the dissociation from 3 body decay is very large.  J/  dissociation will become smaller only near T c 1.Reported on the quarkonium parton dissociation cross section at NLO in QCD  Result depends of wave function or size