Zebo Tang, 高能核物理导论 1 10/10/2009 唐泽波 中国科学技术大学近代物理系 相对论重离子碰撞中 J/  的产生 Introduction J/  production at low p T J/  production at high p T

Zebo Tang, 高能核物理导论 2 10/10/2009 Discovery of J/  PRL33, (1974) PRL33, (1974)

Zebo Tang, 高能核物理导论 3 10/10/2009 Features of J/  cc bound state, r~0.4 fm Mass=3.097 GeV/c 2, Width=93.2 keV/c 2

Zebo Tang, 高能核物理导论 4 10/10/2009 Charmonium production mechanism NRQCD Color singlet Color octet Color singlet model (CSM), LO underpredicted CDF data by order of magnitude Color octet model (COM), LO good agreement with CDF cross section disagreement with CDF polarization LO Know your reference! LO CSMLO COM J/  3S13S1 CDF measurement: PRL79,572

Zebo Tang, 高能核物理导论 5 10/10/2009 Charmonium production mechanism NRQCD Color singlet Color octet Color singlet model (CSM), LO underpredicted CDF data by order of magnitude Color octet model (COM), LO good agreement with CDF cross section disagreement with CDF polarization CSM*, NLO better agreement NNLO* applicable at p T >5-7 GeV/c COM* improvement of polarization, NLO will come, valid at p T >3 GeV/c Decay feeddown (CDF):  (2s): 7%-15%, slightly increase with p T  c0,1,2 : ~30%, slightly decrease with p T B: Strong p T dependence LO Know your reference!

Zebo Tang, 高能核物理导论 6 10/10/2009 Low p T spectra in p+p CSM+s-channel cut works well at intermediate p T

Zebo Tang, 高能核物理导论 7 10/10/2009 High p T spectra in p+p Significantly extend previous measurements from 5 to 14 GeV/c CEM, LO COM describe overall trend, leave little to no room for feeddown NNLO* CSM, steeper than data STAR Preliminary

Zebo Tang, 高能核物理导论 8 10/10/2009 x T scaling n is related to the number of point-like constituents taking an active role in the interaction n=8: diquark scattering n=4: QED-like scattering  and proton at p T >2 GeV/c: n=6.6±0.1 ( PLB 637, 161(2006)) J/  at high p T : n=5.6±0.2 (close to CS+CO prediction) Soft processes affect low p T J/  production p T >2 GeV/c STAR Preliminary p T >5 GeV/c

Zebo Tang, 高能核物理导论 9 10/10/2009 Polarization Cesar Luiz da Silva, QM2009

Zebo Tang, 高能核物理导论 10 10/10/2009 Feeddown R(ψ ’ ) =8.6±2.5% PHENIX R( c ) <42% (90%C.L.) PHENIX  c → J/  +  Susumu X. Oda, QM2008

Zebo Tang, 高能核物理导论 11 10/10/2009 Disentangle contributions via Correlations J/  -hadron correlation can also shed light on different source contribution to J/  production CSM vs. COM 1) no near side correlation 2) strong near side correlation PLB 200, 380(1988) and PLB 256,112(1991)

Zebo Tang, 高能核物理导论 12 10/10/2009 B  J/  No significant near side correlation B contribution (13  5) % Little room for parton fragmentation STAR Preliminary arXiv:

Zebo Tang, 高能核物理导论 13 10/10/2009 Quark Gluon Plasma Quark Gluon Plasma: 1)Deconfined and 2)Thermalized state of quarks and gluons

Zebo Tang, 高能核物理导论 14 10/10/2009 Color screening of heavy quarks J/  dissociation due to color screening  Signature of the QGP formation Á gnes M ó csy, QM2009 T. Matsui and H. Satz, PLB178, 416 (1986) 23 years story

Zebo Tang, 高能核物理导论 15 10/10/2009 Plasma Thermometer ? Quarkonium dissociation temperatures – Digal, Karsch, Satz Á gnes M ó csy, QM2009

Zebo Tang, 高能核物理导论 16 10/10/2009 J/  suppression in heavy-ion collisions Peripheral Central 200 AGeV O+U collisions NA38, PLB220, 471 (1989)

Zebo Tang, 高能核物理导论 17 10/10/2009 Nuclear absorption Inelastic J/ scattering (dissociation) on primordial target and projectile nucleons  suppression of J/ Before the formation of QGP  nothing to do with QGP  Cold nuclear matter (CNM) effect A. Sibirtsev, K. Tsushima and A. W. Thomas, PRC63, C. Gerschel and J. Hufner, PLB 207, 253 (1988)

Zebo Tang, 高能核物理导论 18 10/10/2009 Description of absorption Fully explained the J/ suppression No screening effect? C. Gerschel and J. Hufner, Z. Phys. C 56, 171 (1992)

Zebo Tang, 高能核物理导论 19 10/10/2009 Anomalous J/  suppression NA50, NPA 610, 404 (1996)

Zebo Tang, 高能核物理导论 20 10/10/2009 Anomalous J/  suppression NA50, Eur. Phys. J. C 39, 335 (2005) A signal of QGP formation within a “ threshold-suppression ” scenario J. P. Blaizot and J. Y. Ollitraut, PRL 77, 1703 (1996)

Zebo Tang, 高能核物理导论 21 10/10/2009 Evidence of deconfinement NA 50, PLB 477,28 (2000) cc direct J/

Zebo Tang, 高能核物理导论 22 10/10/2009 More CNM effects

Zebo Tang, 高能核物理导论 23 10/10/2009 Shadowing/anti-shadowing P. Amaudruz et al., NPB 441, 3 (1995) S. R. Klein and R. Vogt, PRL 91, (2003)

Zebo Tang, 高能核物理导论 24 10/10/2009 Cronin effect Main features:  p T 2  (and T) linearly increase with L (mean thickness of nuclear matter) Phenomenological description with the expression with an energy dependent  p T 2  pp and a common slope:  gN = 0.081±0.002 (GeV/c) 2 /fm Multi-scattering of the incoming gluon

Zebo Tang, 高能核物理导论 25 10/10/2009 Hadronic co-mover dissociation Sergei G. Matinyan and Berndt Muller, PRC 58, 2994 (1998) S. Gavin, M. Gyulassy and A. Jackson, PLB 207, 257 (1988) R. Vogt, M. Prakash, P. Koch and T. H. Hansson, PLB 207, 263 (1988) Inelastic J/ scattering (dissociation) on secondary produced hadronic comovers  Suppression of J/  Nothing to do with QGP  Another CNM effect

Zebo Tang, 高能核物理导论 26 10/10/2009 Parton-induce break-up in QGP The anomalous suppression depends on our understanding of CNM effects

Zebo Tang, 高能核物理导论 27 10/10/2009 Move to higher energy

Zebo Tang, 高能核物理导论 28 10/10/2009 J/  suppression at RHIC Similar suppression as that at SPS More suppression at forward rapidity Global error = 7% Global error = 12% Scomparin (proc. QM06) : nucl-ex/

Zebo Tang, 高能核物理导论 29 10/10/2009 CNM constraints from dAu results

Zebo Tang, 高能核物理导论 30 10/10/2009 CNM constraints from dAu results Mid-rapidityForward/backward rapidity

Zebo Tang, 高能核物理导论 31 10/10/2009 Forward rapidity high x low x Gluon saturation from non-linear gluon interactions for the high density at small x; amplified in a nucleus. Kharzeev, Levin, Nardi and Tuchin, 2009 Normal CNM descriptions (blue) give similar (or even smaller) suppression at mid vs forward rapidity but if peaking in “anti-shadowing” region were flat instead (red dashed) then one would get larger suppression for forward rapidity as has been observed in AuAu data Mike Leitch, WWND 2008

Zebo Tang, 高能核物理导论 32 10/10/2009 Mid-rapidity Why the J/ suppression is similar at RHIC as that at SPS? 1)Regeneration 2)Sequential suppression

Zebo Tang, 高能核物理导论 33 10/10/2009 Regeneration Grandchamp, Rapp, Brown PRL 92, (2004) nucl-ex/ Regeneration models give enhancement that compensates for screening larger gluon density at RHIC expected to give stronger suppression than SPS but larger charm production at RHIC gives larger regeneration very sensitive to poorly known open- charm cross sections forward rapidity lower than mid due to smaller open-charm density there expect inherited flow from open charm regeneration much stronger at the LHC! Issues: need to know what happens to  C &  ’ & measure J/  flow flat forward/mid RAA seems inconsistent with increasing regeneration & screening for more central collisions Mike Leitch, WWND 2008

Zebo Tang, 高能核物理导论 34 10/10/2009 J/  elliptic flow Inherit open charm flow or not? Regeneration? Too early to compare to models, need more statistics

Zebo Tang, 高能核物理导论 35 10/10/2009 Sequential suppression H. Satz, Nucl. Phys. A (783): (2007) J/  suppression at low p T maybe only from excited stats (  ’,  c ) F. Karsch, D. Kharzeev and H. Satz, PLB 637, 75 (2006) 60% from direct J/  : not suppressed 30%  c and 10%  ’: dissociated NA50, EPJ39,335 NA60, QM05

Zebo Tang, 高能核物理导论 36 10/10/2009 Move to high p T

Zebo Tang, 高能核物理导论 37 10/10/2009 Hot-wind dissociation J/  H. Liu, K. Rajagopal and U.A. Wiedemann PRL 98, (2007) and hep-ph/ M. Chernicoff, J. A. Garcia, A. Guijosa hep-th/ Possible to observe J/  suppression from directly produced J/  at high p T

Zebo Tang, 高能核物理导论 38 10/10/2009 Jet energy loss STAR: PRL98(2007) Strong suppress, energy loss Similar magnitude as light hadrons PHENIX: PRL98(2007) c/b  e hard parton path length L Quark

Zebo Tang, 高能核物理导论 39 10/10/2009 Nuclear modification factor R AA Consistent with no suppression at high p T : R AA (p T >5 GeV/c) = 1.4± 0.4±0.2 All RHIC measurements: R AA (p T >5 GeV/c) = 1.1 ± 0.3 ± 0.2 Indicates R AA increase from low p T to high p T Contrast to AdS/CFT+ Hydro prediction H. Liu, K. Rajagopal and U.A. Wiedemann PRL 98, (2007), T. Gunji, JPG 35, (2008) How does production mechanism (CS vs. CO) affect energy loss? Good jobs: transport+hydro: from initial produced instead of regenerated Y.Liu, Zhen Qu, N. Xu and P. Zhuang, arXiv: ; N. Xu, QM2009 two-component model: leakage and B feeddown is important R. Rapp, X. Zhao, arXiv: Anti-shadowing?

Zebo Tang, 高能核物理导论 40 10/10/2009 Upsilon Consistent with N bin scaling Cold Nuclear Matter effects (Shadowing) are not large. preliminary R AuAu in progress

Zebo Tang, 高能核物理导论 41 10/10/2009 Summary  J/ is a unique probe of the hot dense matter produced in heavy-ion collisions  Lots of CNM effects need to be considered  On the way to understand the screening better  As well as J/ production mechanism in hadron collisions