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Status and Future Perspective of J/ y Measurement in Heavy Ion Collisions

Heavy Ion Café: 2008/6/28 T. Gunji. Title. 1/42. Status and Future Perspective of J/ y Measurement in Heavy Ion Collisions. T. Gunji Center for Nuclear Study University of Tokyo. Heavy Ion Café: 2008/6/28 T. Gunji. Outline. 2. Outline. Introduction Physics Motivation

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Status and Future Perspective of J/ y Measurement in Heavy Ion Collisions

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  1. Heavy Ion Café: 2008/6/28 T. Gunji Title 1/42 Status and Future Perspective of J/y Measurement in Heavy Ion Collisions T. Gunji Center for Nuclear Study University of Tokyo

  2. Heavy Ion Café: 2008/6/28 T. Gunji Outline 2 Outline • Introduction • Physics Motivation • Charmonium and the Medium • Results from SPS and RHIC • Future Perspective • Summary

  3. Heavy Ion Café: 2008/6/28 T. Gunji Introduction 3 J/y family (J/y, y’, cc) • Bound system between ccbar. • mc~1.3 GeV • Heavy and small system. • Long lived (compared to LVM [r,w,f] ) • Can be measured via di-lepton decay. T. Gunji, D-thesis

  4. Heavy Ion Café: 2008/6/28 T. Gunji Introduction 4 Feed down from excited states • J/y = direct J/y + feed down from y’ and cc 20% ~ 40% from cc ~ 10% from y’ S. X. Oda QM2008

  5. Heavy Ion Café: 2008/6/28 T. Gunji Physics Motivation 5 Color Screening • When Quark-Gluon-Plasma is formed, the attraction between ccbar pairs is reduced due to the color screening. • T. Matsui and H. Satz (1986) This leads to the suppression of quarkonia yield. tccbar~ 0.06fm, exp(-2mc/Tc)~10-7 T. Matsui and H. Satz PLB 178, 416, (1986) Suppression depends on temperature of the medium and radius of qqbar system.

  6. Heavy Ion Café: 2008/6/28 T. Gunji Physics Motivation 6 T/TC 1/r [fm-1] (1S) J/(1S) b’(2P) c(1P) ’’(3S) ’(2S) Melting Temperatures Potential Model & lattice simulations S. Digal, F. Karsch and H. Satz A.Mocsy HP2008 J/y cc hc T. Hatsuda QM2006 (hep-ph/0702293) Datta, Karsch, Petreczky & Wetzorke, hep-lat/0312037 Asakawa & Hatsuda, hep-lat/0308034 Tc~270 MeV Aarts et al., hep-lat/0610065 J/y may survive up to 2Tc, while cc and y’ are melt at 1.1Tc . Other results: cc may survive up to ~2Tc. [T. Umeda, PRD. 75, 094502 (07)] J/y may be dissolved at ~1.2Tc. [A. Mocsy et al, PRL 99(2007)211602, HP’08]

  7. Heavy Ion Café: 2008/6/28 T. Gunji Physics Motivation 7 pT dependence of Screening • Leakage effect • high pT J/y can escape the medium. • depends on formation time. (medium vs. J/y) • Hot-wind scenario • Melting temperature depends on relative velocity between J/y and medium. M.C.Chu and T. Matsui PRD 37 (1998) 1851 H. Liu et al. hep-ph/0607062

  8. Heavy Ion Café: 2008/6/28 T. Gunji Physics Motivation 8 Experiment at SPS and RHIC • Heavy Ion Collisions  Study of QGP • J/y measurement in heavy ion collisions has been performed at SPS and RHIC. LEP/LHC SPS PHENIX STAR • NA38/NA50/NA51/NA60 • √sNN ~ 17-20 GeV • S+U, p+p, p+d, p+Pb, Pb+PB, In+In ……. • PHENIX/STAR • √sNN = 200 GeV (x10 SPS) • p+p, d+Au, Cu+Cu, Au+Au

  9. Heavy Ion Café: 2008/6/28 T. Gunji Charmonium and the Medium 9 Fate of J/y in Heavy Ion Collisions • All stage of collisions modify the J/y yield. Nuclear medium Hadronic Matter Initial stage Hot and dense medium • Gluon • Shadowing • CGC • Nuclear • Absorption • Cronin • Color • screening • Gluon dissociation • Recombination • Comover • DDbar • J/y+h

  10. Heavy Ion Café: 2008/6/28 T. Gunji Charmonium and the Medium 10 Initial State Effects Eskola et al. NPA696 (2001) 729 gluons in Pb / gluons in p • Gluon Shadowing • Depletion of Gluon PDF in nuclei • Color Glass Condensate • Gluon saturation from non-linear gluon interactions for the high density at small x • Larger effect for heavier nuclei SPS : x~0.1 RHIC: x~10-2 LHC: x~3x10-4 Shadowing Anti Shadowing x

  11. Heavy Ion Café: 2008/6/28 T. Gunji Charmonium and the Medium 11 J/ψ L Cold Matter Effects • Nuclear Absorption • Dissociation of J/y or pre-resonance by spectators. • Cronin effect • Multiple scattering of partons • σabs = 4.18 ± 0.35 mb • at SPS

  12. Heavy Ion Café: 2008/6/28 T. Gunji Charmonium and the Medium 12 Recombination • Recombination of J/y from uncorrelated ccbar pairs • P = Nccbar/Nh, NJ/y = Nccbar2/Nh • Nccbar(Nh) scales with Ncol(Npart). • Nccbar grows faster with CMS energy • Negligible at SPS. But not at RHIC. Huge at LHC. • Charm production needs to be understood. • Two models: • Statistical hadronization (A. Andronic et al.) • Formation at phase boundary according to statistical law. • Kinetic formation (R. Rapp et al.) • In-medium formation and destruction by thermal gluons.

  13. Heavy Ion Café: 2008/6/28 T. Gunji Charmonium and the Medium 13 Screening and Gluon Dissociation • Medium effects on J/y suppression • Color screening : collective effect • ccbar is not bound to form J/y • Dissociation of J/y by (thermal) gluons • If J/y is formed, energetic gluons (comoving hadrons) could dissociate J/y. J/y + g  ccbar (+g) • Both depends on: • formation time of QGP and J/y (t8~0.3fm) • field map of T and r and its space-time evolution • Screening : melting temperature and decay width • Dissociation: cross section (decay width) They are crucial and to be understood in detail to study the J/y suppression and compare to the experimental data.

  14. Heavy Ion Café: 2008/6/28 T. Gunji Charmonium and the Medium 14 G X.N.Wang PLB540 (2002) 62 ¼ sc+g sJ/y+g Td Gluon dist. (T=0.35 GeV) k[GeV] Decay width ? • How it behaves around Tdiss? • Screening: Lattice knows? • Dissociation: Rely on pQCD? • Cross section of J/y+g->cc(g) • Reliable in QGP? Reliable for higher states? G. Bhanot NPB 156 (1979) 3916 R. Rapp et al hep-ph/0502208 • Decay width (cross section with gluons) in QGP is most important quantity to study J/y suppression (even for recombination) • How much it is understood in detail?

  15. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 15 Results from SPS P. Cortese HP2008 • Cold Matter effects • p+A @400/450 GeV (NA50) • p+A @400/158 GeV (NA60) Stronger suppression than the cold matter effects @ Npart>150. Very preliminary P. Cortese HP2008 P. Cortese HP2008

  16. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 16 pT dependence of Suppression L. Ramello QM2005 • Suppression at low pT (<2-3 GeV) • Cronin effect • Leakage effect. No hot-wind effect(?) R. Arnaldi QM2008

  17. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 17 Pb-Pb @ 158 GeV NA60 In-In 158 GeVpreliminary J/y suppression at SPS (1/2) • Dissociation by thermal gluons R. Rapp PLB92 (2004) 212301 X.N.Wang PLB540 (2002) 62 100 20 40 ET [GeV] J/y +g  ccbar (pQCD) J/y +g  ccbar +g

  18. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 18 J/y suppression at SPS (2/2) • Sequential Suppression (screening) • Only y’ and cc melt. (~40%) • S (J/y) = 0.4*S(cc, y’)+0.6 • Well agreement with data F. Karsch et al., PLB, 637 (2006) 75 J/y y’

  19. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 19 NA60 v2 of J/y at SPS HP2008 NA50 • NA50/NA60 (Pb+Pb, In+In) • Large v2 • Difficult to understand • Ncc is low (no recombination) • No charm thermalization • Due to anisotropic absorption in QGP/nuclear matter? HP2008 R. Arnaldi QM2008 v2 X.N.Wang PLB540 (2002) 62

  20. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 20 RAA vs. Npart at RHIC |y|<0.35 1.2<|y|<2.2 PRL.98, 232301 (2007) arXiv:0801.0220 RAA (1.2<|y|<2.2) < RAA (|y|<0.35) ~ RAA at SPS (0<y<1) Why? Why?

  21. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 21 pT dependence of RAA PRL.98, 232301 (2007) QM2008 • Suppression is low pT J/y (<5GeV).

  22. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 22 Cold Matter Effect in d+Au at RHIC PRC 77 024912 (2008) • Breakup cross section • d+Au collisions F. Fleuret HP2008 • Break up cross section is compatible to SPS. • Need more statistics to constraint cold matter effects.

  23. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 23 RAA vs. Cold Matter effect • Extrapolate Cold Matter effect to Au+Au. EKS shadowing model arXiv:0801.0220 • J/y suppression starts at: • Npart~200 at mid-rapidity • Npart~100 at forward rapidity • RAA(1.2<|y|<2.2) < RAA (|y|<0.35) 1: Dissociation + Recombination dissociation should be similar but recombination is larger at mid-y. 2: Initial state effect (CGC) Suppression of J/y production at forward-y due to CGC effect. • RAA(RHIC |y|<0.35) ~ RAA (SPS) 1: Stronger dissociation at RHIC supplemented by Recombination 2: Sequential melting and Melting J/y at higher temperature

  24. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 24 Statistical Hadronization NPA 789 (2007) 334, PLB 652 (2007) 259, PLB 659 (2008) 149 • A. Andronic et al. • assuming: No survival J/y above Npart>80 input output gc I1/I0 Input charm y distribution ds/dy=63 mb ds/dy=123 mb (PHENIX)

  25. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 25 Kinetic formation • R. Rapp et al. L. Yan et al.….. L. Yan et al. R. Rapp et al. PRL 97 (2006) 232301 arXiv:0712.2407 J/y+gc+c RAA How we precisely know decay width of J/y in QGP? Npart

  26. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 26 Comover + Recombination Tywoniuk QM08, arXiv:0712.4331 • A. Capella et al. • SPS: Comover alone with sco = 0.65mb • Good for Pb+Pb but Failed for In+In • RHIC: inclusion recombination Number of binary col. Multiplicity in p+p Non-diffractive p+p cross section

  27. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 27 Effect of Color Glass Condensate • Saturation could suppress forward J/y in Au+Au • First numerical estimate, work in progress • M. Nardi, D. Kharzeev, E. Levin, K. Tuchin @ QM2008 • Calculations based on CGC can reproduce y and b dependence of J/y in Au-Au at RHIC. • Some uncertainty in absolute normalization, leaving room for final state suppression.

  28. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 28 Sequential Melting at RHIC T. Gunji et al. Phys. Rev. C 76:051901 (R), 2007 • Hydro + J/y Model • First attempt for the study of sequential suppression of charmonia at RHIC. • Incorporate J/y, cc and y’ into the evolution of matter. • Evolution of matter : (3+1)-dimentional relativistic hydrodynamics • T. Hirano and Y. Nara, PRL 91, 082301, (2003) • T. Hirano and Y. Nara, PRC 69, 034908, (2003) • T. Hirano and K. Tsuda, PRC 66, 054905, (2002) • http://tkynt2.phys.s.u-tokyo.ac.jp/~hirano/parevo/parevo.html • J/y, cc and y’ : impurity traversing through the matter • Assume three kinds of interaction inside QGP. • Free Streaming • Hot-Wind • Complete Thermalization

  29. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 29 b (pT) f x0 J/y Modeling of J/y suppression • Survival Prob. In the medium: • Decay Width: • Motion of J/y: free streaming • Total Survival Prob. • Free Parameters: • (TJ/y, Tc, fFD ) • x0(Production point) is • distributed according to the • spatial Ncol distribution. • pTis distributed according to • the measured J/y distribution. • J/y azimuthal angle, F, • is flat (0 to 2p).

  30. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 30 Results • Compare survival probability in the medium. • Best Fit @ (TJ/y, Tc, fFD) = (2.00Tc, 1.34Tc, 10%) • Onset of J/y suppression at Npart ~ 160. • Gradual decrease of SJ/ytotabove Npart~160 reflects that the transverse area with T>TJ/yincreases. • Very sensitive to TJ/yand TJ/y is consistent with lattice results.

  31. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 31 Decay width below Tmelt T. Song, Y. Park and S. H. Lee Phys.Lett.B659:621-627,2008. • Decay width below TJ/y is very small. • a<0.20

  32. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 32 Other observables Free streaming Hot-wind  SAA vs. pT • Suppression is flat in case of • free streaming and stronger • for high pT J/y in case of hot-wind. 20-30% 0-10% Free streaming Hot-wind 40-50% 3% 0-10% 0-10% 20-30% 20-30% v2 vs. pT  3% • v2 is small (<1%) in case of free • Streaming and larger for higher pT • in case of hot-wind (~3% v2). 40-50% 50-60%

  33. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 33 J/y v2 at RHIC • Need more data!! • Challenging to understand both SPS and RHIC data. • Negative v2 is possible, when J/y is formed via recombination like light hadrons and charm quarks locally equilibrated. Just Mass Ordering!! NA50 D. Krieg et al. arXiv:0806.0736

  34. Results from SPS and RHIC Heavy Ion Café: 2008/6/28 T. Gunji 34 Where we are now? Where we go? Yes sequential suppression (J/y melt at RHIC) dissociation + recombination (same amount btw. mid and forward) CGC • Now. • Need to study: • Decay width of quarkonia states in QGP (vs. T) • Charm production and recombination • Initial state effect such as CGC. • y’, cc, U states, v2, pT dist. … • High statistics data from RHIC (d+A, A+A)!! • Go to higher energy (temperature). LHC!! No Dissociation +Recombination Decay width? charm production?

  35. Heavy Ion Café: 2008/6/28 T. Gunji Future Perspective 35 RHIC Run8 d+Au collisions ~30 times larger stat. compared to run3 4,369 J/  ee (~6,000 from all data) 59 nb-1 simulation expected accuracy 57,030 J/   (~73,000 from all data) 63 nb-1 Expected improvement in constraints of cold matter effect (red) compared to Run3 (blue)

  36. Heavy Ion Café: 2008/6/28 T. Gunji Future Perspective 36 RHIC future • PHENIX upgrade • NCC, forward VTX (J/y/y’, cc at forward) • STAR upgrade • Forward muon, full EMC+TOF, HFT • Luminosity M. Leitch WWND2008 #J/ # x100 max J/ &    min 100,000 J/   and ~250    per year at highest RHIC luminosities

  37. Heavy Ion Café: 2008/6/28 T. Gunji Future Perspective 37 Central collisions SPS RHIC LHC s (GeV) 17 200 5500 CMS dNch/dy 430 700 1-3103 e (GeV/fm3) 3 5-10 15- 60  3 - 6 LHC-b Vf(fm3) 103 7x103 2x104  2 ALICE T / Tc > 1 2 3-4 ATLAS Large Hadron Collider at CERN • Starts its operation from this summer!! K. Shigaki JPS2008 • 2008 p+p, s = 0.9/10 TeV • 2009 p+p, s = 14 TeV, 1032 cm-2s-1 • Pb+Pb, sNN = 5.5 TeV, 5×1025 cm-2s-1 • 2010~ • p+p, s = 14 TeV, 1031 cm-2s-1 • ,s = 5.5 TeV, 1031 cm-2s-1 • Pb+Pb, sNN = 5.5 TeV, 1027 cm-2s-1 • p+Pb, sNN = 8.8 TeV, 1029 cm-2s-1 • Ar+Ar, sNN = 6.3 TeV, 1029 cm-2s-1 • LHC: ~ 30x larger in √sNN w.r.t. RHIC • T ~ 1.5-2 x RHIC • e ~ 3-6 x RHIC

  38. Heavy Ion Café: 2008/6/28 T. Gunji Future Perspective 38 enhanced recombination complete suppression SPS RHIC LHC 30 Impact on Quarkonia measurement • Large production cross section • x100 RHIC for bottom • x10 RHIC for charm • Cleary see J/y enhancement or strong suppression K. Itakura QM05 • Much smaller x than at RHIC • down to x~10-4 with charm at y=0 • CGC, PDF … • Bottomonia suppression •  would melt only at LHC • ’ Td ~ J/ Td • Small  regeneration • ’ can unravel J/ suppression vs. regeneration X1,2 = M/√s ey

  39. Heavy Ion Café: 2008/6/28 T. Gunji Future Perspective 39 ALICE • J/y, ϒee at mid-rapidity • |h|<0.9 • ITS+TPC: p • TPC+TRD: eID • J/y, ϒmm at forward-rapidity • -4<h<-2.5 CNS, Tsukuba: TRD Hiroshima: PHOS

  40. Heavy Ion Café: 2008/6/28 T. Gunji Future Perspective 40 Acceptance • Wide y and pT coverage • ALICE: J/y and ϒ • ATLAS and CMS : ϒ

  41. Heavy Ion Café: 2008/6/28 T. Gunji Future Perspective 41 Physics Performance • ALICE Physics Performance Report Vol. 2: J. Phys. G 32 1295 (2006) • Di-electron Mass dist. in Pb+Pb (one year) • nPDF+shadowing+HIJING(<dN/dy>~3000) • Separations of J/y, y’ and ϒ,ϒ’, and ϒ’’. • Di-muon Mass dist. in Pb+Pb (central)

  42. Heavy Ion Café: 2008/6/28 T. Gunji Summary 42 Summary • J/y suppression characterizes the properties of QGP. But • Production of J/y in heavy ion collisions is complicated. • initial ~ cold matter ~ screening, dissociation, recombination… • Feed down from higher states • SPS: sequential melting or gluon dissociation. • Conclusion depends on the decay width (step-like vs. pQCD base) prevents the firm conclusion (even at RHIC!!). • RHIC: “SPS + CGC” or “SPS + Recombination (mid-y)” • Charm production is key for recombination. (especially y dist.) • Need to do and future… • precise calculation of the decay width in “QGP” (vs. T). • study of initial state effect • high statistics (charm production, CGC, cold matter, v2, pT dist.) • simultaneous study at “RHIC+LHC”. LHC!!

  43. Backup slides

  44. Heavy Ion Café: 2008/6/28 T. Gunji Introduction 5 Production (in vacuum) • Production of ccbar pairs • mc~1.3 GeV • as(mc)«1. Pertubavative. • t~ 1/2mc. Process takes place in short time. • Hadronization • Color Singlet Model (pQCD) • Color Evaporation Model • Color Octet Model (NRQCD) • t8 ~ 1/sqrt(2mcLQCD)=0.25fm • Still working hard: • pT distribution, polarization (CDF, RHIC). • feed down, J/y-h correlation (RHIC) H. D. Sato

  45. Heavy Ion Café: 2008/6/28 T. Gunji Results from SPS and RHIC 4 pT dist. of J/y Statistical hadronization A. Andronic et al. nucl-th/0611023, Nucl.Phys.A789:334-356,2007

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