Quarkonia from SPS to RHIC Raphaël Granier de Cassagnac LLR – École polytechnique / IN2P3 Early Time Dynamics in Heavy Ion Collisions Montréal, 2007, July 16 th and from pA to AA

The “normal” introduction… In 1986, Matsui & Satz predicted an “unambiguous” signature of QGP –Disappearance of quarkonia above a certain temperature / energy density threshold Where do we stand today? –What is the J/ψ nuclear modification factor? –Remembering that heavy flavours should and do scale with N coll R AB = N ψ AB N ψ PP x Matsui & Satz, PLB178 (1986) 416 PHENIX, PRL94 (2005) , July 16th Quarkonia from SPS to RHIC - 2/29

J/ψ in AA, the experimental facts PHENIX: PRL 98 (2007) NA50: EPJ C39 (2005) 335 NA60: nucl-ex/ , to appear in PRL

R AuAu (y~0) > R AuAu RHIC, more J/ψ suppression at forward rapidity ! R AA (y~1.7) R AA (y~0) 60% PHENIX, PRL98 (2007) , July 16th Quarkonia from SPS to RHIC - 4/29

R AuAu vs R Wait for Cu+Cu, still preliminary, soon final… PHENIX, PRL98 (2007) CuCu in nucl-ex/ PHENIX, PRL98 (2007) CuCu in nucl-ex/ , July 16th Quarkonia from SPS to RHIC - 5/29

R AuAu (y~0) ~ R AuAu (SPS) Lower rapidity R AA look surprisingly similar, while there are obvious differences: –At a given N part, different energy densities… –Cold nuclear matter effects (x Bjorken, σ abs …) –… PHENIX, PRL98 (2007) Scomparin’s QM06 PHENIX, PRL98 (2007) Scomparin’s QM , July 16th Quarkonia from SPS to RHIC - 6/29

First, beware of cold nuclear matter (CNM) effects !

gluons in Pb / gluons in p x Cold nuclear matter effects ? Many possible effects: –J/ψ (or cc) absorption –(Anti) shadowing (gluon saturation, CGC…) –Energy loss of initial parton –p T broadening “Cronin “ –Complications from feeddown ψ’ & χ c ? –Something else ? Not well predicted, need pA (or dA) measurements! Eskola, Kolhinen, Vogt, NPA696 (2001) 729 An example of gluon shadowing prediction Anti Shadowing 2007, July 16th Quarkonia from SPS to RHIC - 8/29

Cold nuclear SPS Normal nuclear absorption alone does a splendid job in describing pA, SU, and peripheral PbPb & InIn… –(including preliminary 158 GeV from NA60) exp(-σ abs ρ 0 L) –(or in Glauber model) –σ abs = 4,18 ± 0,35 mb –L nuclear thickness: NA50, EPJ C39 (2005) 335 & Scomparin’s QM06 talk NA50, EPJ C39 (2005) 335 & Scomparin’s QM06 talk J/ψ L J/ψ / DY rescaled to 158 GeV NA60 preliminary σ abs = 4,18 ± 0,35 mb 2007, July 16th Quarkonia from SPS to RHIC - 9/29

Something SPS? Do we fully understand SPS ? Not these surprising rapidity distribution asymmetries  –Variation of ~30 to ~50% in one unit of rapidity ! –Seems large to be (anti)shadowing… –Not taken into account in CNM extrapolation… +50% +30% NA50, EPJ. C48 (2006) 329 J/ψ yield 2007, July 16th Quarkonia from SPS to RHIC - 10/29

Only centrality dependence in dA (or pA) of J/ψ production ! ~ 10% global error not to be forgotten… Reproduced by Ramona Vogt –Black lines: EKS98 shadowing + σ abs = 0 to 3 mb –Colored lines: FGS shadowing + σ abs = 3 mb Favoring moderate shadowing + moderate absorption… R dAu Cold nuclear RHIC PHENIX, PRL96 (2006) Klein,Vogt, PRL91 (2003) PHENIX, PRL96 (2006) Klein,Vogt, PRL91 (2003) y = +1.8 y = 0 y = – , July 16th Quarkonia from SPS to RHIC - 11/29

From dA to RHIC What’s on the market? 1.Modeling nuclear absorption + inhomogeneous (anti)shadowing –Vogt, nucl-th/ exp –(σ diss (y)+σ diss (-y))ρ 0 L –Karsch, Kharzeev & Satz, PLB637(2006)75 –σ diss from fit on dAu data –Assume exp (-σ diss ρ 0 L) –No error propagation 3.dAu data driven Glauber approach –RGdC, hep-ph/ –Fit RdA(b) → 2007, July 16th Quarkonia from SPS to RHIC - 12/29

From dA to RHIC b1b1 b2b2 b AA = x J/ψ = x J/ψ RGdC, hep-ph/ For a given A+A collision at b AA, Glauber provides a set of N+N collisions occurring at b i 1 and b i 2 One minimal assumption is rapidity factorization: R AA (|y|,b AA ) = Σ collisions [R dA (-y,b i 1 ) x R dA (+y,b i 2 )] / N coll Works (at least) for absorption & shadowing since production ~ pdf1 x pdf2 x exp –ρσ(L 1 +L 2 ) 2007, July 16th Quarkonia from SPS to RHIC - 13/29

R AA from cold nuclear matter Two CNM methods agree quite well: EKS shadowing+absorption by Vogt & dA-driven Glauber by RGdC Clear anomalous suppression y~1.7) R. Vogt, nucl-th/ RGdC, hep-ph/ R. Vogt, nucl-th/ RGdC, hep-ph/ y~1.7 y~0 2007, July 16th Quarkonia from SPS to RHIC - 14/29

Temptation to divide RAA / CNM is great, but beware of p+p baselines !

p+p cross section vs rapidity Different p+p references used for R AA and R dA J/ψ survival probability ~ R AA / (R dA ) 2 = (AA/run5pp) / (dA/run3pp) 2 Run3pp < Run5pp –More suppression from CNM have to be taken into account… –(run5pp/run3pp) 2 = y=1.7 –(run5pp/run3pp) 2 = y=0 ! –But systematic errors cancelation to be revisited… –Work in progress in PHENIX… –For now ~ 30% syst. error ! Is σ abs really ? PHENIX, PRL96 (2006) PHENIX, PRL98 (2007) PHENIX, PRL96 (2006) PHENIX, PRL98 (2007) (symmetrized distributions) 2007, July 16th Quarkonia from SPS to RHIC - 16/29

R AA / RHIC ±35% global systematics ±30% global systematics J/ψ survival beyond CNM First R AA /CNM extraction including (proper) error propagation –d+Au and p+p errors –Systematics from Glauber & function used for RdA(b) Boxes are correlated errors from AuAu & dominant CNM Accounting for all errors : –S(J/ψ) = 44 ± –S(J/ψ) = 25 ± in the most central collisions… 44± 23% 25±12% RGdC, hep-ph/ , July 16th Quarkonia from SPS to RHIC - 17/29

R AA / RHIC & SPS At mid-rapidity, the amount of surviving RHIC is still compatible with SPS (~60%) but depends a lot on CNM (and pp references)… At forward rapidity, RHIC anomalous suppression is much stronger ! ±11% global systematics ±35% global systematics ±30% global systematics J/ψ survival beyond CNM 44± 23% 25±12% RGdC, hep-ph/ , July 16th Quarkonia from SPS to RHIC - 18/29

Now… What’s going on with the anomalous suppression ?

What’s going ? Several models could fit NA50 –Plasma (either thermal or percolative) –Comovers (hadronic or partonic ?) Now NA60… –Difficult to reproduce… Satz, Digal, Fortunato Rapp, Grandchamp, Brown Capella, Ferreiro Percolation Plasma Comovers See Carlos Lourenço’s talk… 2007, July 16th Quarkonia from SPS to RHIC - 20/29 Roberta Arnaldi, QM05 Final in nucl-ex/ Roberta Arnaldi, QM05 Final in nucl-ex/

(no cold effects) Digal, Fortuno, Satz, EPJC32 (2004) 547 Digal, Fortuno, Satz, EPJC32 (2004) 547 “NA50 only” RHIC Most of the models that did a good SPS RHIC –Gluon dissociation (y~0) doesn’t give the right trend and/or amount of suppression –Comovers (of unknown partonic/hadronic nature) give R AA (y=2) > R AA (y=0) –Parton percolation has an onset at N part ~ 90 and simultaneous J/ψ + χ c + ψ’ melting Capella & Ferreiro, hep-ph/ Capella & Ferreiro, hep-ph/ R. Rapp & al., nucl-th/ Yan, Zhuang, Xu, nucl-th/ R. Rapp & al., nucl-th/ Yan, Zhuang, Xu, nucl-th/ , July 16th Quarkonia from SPS to RHIC - 21/29

nucl-th/sequential melting Ratio not (well) known –At least ~10% uncertainty –HERAB: 0.21 χ c ψ’ Faccioli, Hard Probes 06 Theorists still working on temperatures… –Mόcsy melts Tc hep-ph/ –Umeda melts χ c > 1.4 Tc hep-lat/ J/ψ ~ 0.6J/ψ + 0.3χ c + 0.1ψ’ Was a consensus that –J/ψ melt at ~2T c (~32ε c !) –Excited states around 1.1 T c (see eg Satz, hep-ph/ ) See Ágnes Mόcsy’s talk… 2007, July 16th Quarkonia from SPS to RHIC - 22/29

nucl-ex/sequential melting No precise scaling! (blame it on S = y=1.7  direct J/ψ do melt ! Why y~0 ? R AA (y~0) > R AA (y~1.7) ruling out all density- induced suppression effects? ±11% global systematics ±35% global systematics ±30% global systematics Be cautious ! Formation time may be RHIC and SPS SPS 1.6 fm/c crossing time a bit large for Bjorken formula 2007, July 16th Quarkonia from SPS to RHIC - 23/29

Onset curves fit the midrapidity data… –Chaudhury, nucl-th/ –Gunji et al, hep-ph/ (after CNM subtraction) So do smooth curves ! –Nagle nucl-ex/ Density y=0 is incompatible with SPS onset or larger y=1.7 –Linnyk & al, nucl-th/ Density threshold ? Yes ? A.K. Chaudhury, nucl-th/ , July 16th Quarkonia from SPS to RHIC - 24/29 T. Gunji et al, hep-ph/

Density threshold ? No ! See 0lena Linnyk’s talk… J. Nagle, nucl-ex/ Onset curves fit the midrapidity data… –Chaudhury, nucl-th/ –Gunji et al, hep-ph/ (after CNM subtraction) So do smooth curves ! –Nagle nucl-ex/ Density y=0 is incompatible with SPS onset or larger y=1.7 –Linnyk & al, nucl-th/ , July 16th Quarkonia from SPS to RHIC - 25/29

Regeneration ? Various coalescence / recombination approaches… Better match to data –(look in particular Bratkovskaya’s) Depend a lot on poorly known cc reference But can accommodate: –R AA (y=0) > R AA (y=1.7) –Density-induced enhancement mechanism… – flatness R. Rapp et al.PRL 92, (2004) R. Thews et al, Eur. Phys. J C43, 97 (2005) Yan, Zhuang, Xu, PRL97, (2006) Bratkovskaya et al., PRC 69, (2004) A. Andronic et al., NPA789, 334 (2007) R. Rapp et al.PRL 92, (2004) R. Thews et al, Eur. Phys. J C43, 97 (2005) Yan, Zhuang, Xu, PRL97, (2006) Bratkovskaya et al., PRC 69, (2004) A. Andronic et al., NPA789, 334 (2007) 2007, July 16th Quarkonia from SPS to RHIC - 26/29

Unaccounted CNM ? Strong initial states effect ala color glass condensate ? –But they have to violate rapidity symmetrisation R AA (|y|) = R dA (-y) x R dA (+y) –(otherwise taken into account in CNM extrapolation) Could this + sequential melting produce R AA (y~0) and R AA (y~1.7) ? Double ratio should drop… A possibility…  =0  =2 This calc. is for open charm, but similar for J/  ? Tuchin, hep-ph/ R AA (y~1.7) R AA (y~0) 2007, July 16th Quarkonia from SPS to RHIC - 27/29

“Anomalous” conclusions Two qualitative possible RHIC 1.Large melting + some regeneration 2.Initial effects (CGC) + melting (of ψ’, χ c ?) Need better handle of CNM (Run8 RHIC) Need better open charm measurements (Run9+) Smoking gun would have been a J/ψ rise… –W–Wait for LHC… J/ψ v 2 could bring more information –F–Finished run7 should allow to measure → –B–Beware : these are fake points ! All this, assumes deconfinment ! 2007, July 16th Quarkonia from SPS to RHIC - 28/29

Back to the facts Much more than what I discussed… Should help constraint the models… PHENIX, PRL98 (2007) Soon for Cu+Cu… PHENIX, PRL98 (2007) Soon for Cu+Cu… 2007, July 16th Quarkonia from SPS to RHIC - 29/29

Back-up slides

2007, July 16th Quarkonia from SPS to RHIC - Sequential melting ? Before QM06, it was conceivable that only the excited states melt J/ψ ~ 0.6J/ψ + 0.3χ c + 0.1ψ’ (with ~10% uncertainty) Now, survival = (25±12)%  direct J/ψ do ? Why ? Isn’t R AA (y~0) > R AA (y~1.7) ruling out all “density” effects ? Karsch, Kharzeev & Satz PLB637(2006)75 Karsch, Kharzeev & Satz PLB637(2006)75 Please, be careful with this plot ! No systematic uncertainties on PHENIX points No uncertainties from CNM… ε is given by Bjorken formula for  0 = 1fm/c but is the formula applicable for SPS crossing time of 1.6 fm/c ? Repenser ce slide ! Experimental fraction Theoretical idea Mon plot instead ! ±11% global systematics ±35% global systematics ±30% global systematics 31/29

2007, July 16th Quarkonia from SPS to RHIC - Quick look to open charm Through semileptonic decays (D  e) PHENIX, PRL94 (2005) N coll scaling ~25% systematic uncertainties (without Silicon vertex detector upgrade) 10 to 20 cc pairs ! (  40 acc. STAR) 32/29

Open charm R AA & v 2 (p T ) 2007, July 16th Quarkonia from SPS to RHIC - 33/29 PHENIX, nucl-ex/

2007, July 16th Quarkonia from SPS to RHIC - Veterans/newbies balance Grandchamp, Rapp, Brown PRL 92, (2004) nucl-ex/ Yan, Zhuang, Xu, nucl-th/ Thews, Eur.Phys.J C43, 97 (2005) nucl-ex/ Detailed shape is not easy to get! Experimental J/ψ keep falling down… 34/29

2007, July 16th Quarkonia from SPS to RHIC - No dependence of –Maybe a modest rise at forward rapidity No sizeable Cronin 35/29

Heavy flavour workshop in Beijing Latest J/psi from phenix - 36/23 NEW PLOT initial pQCD thermal direct y=1.7 direct y=0 in-medium y=0 in-medium y=1.7 vs recombination ? Initial production depends a lot on initial p T broadening (Cronin effect) –Earlier (run3) dAu/pp data showed clear –Not clear with new (run5) pp data used here not here Yan, Zhuang, Xu, nucl-th/ R. Thews et al, EPJ C43, 97 (2005)

2007, July 16th Quarkonia from SPS to RHIC - QM06 versus QM05 Good agreement ! At forward rapidity, on the lower edge of systematics –(better handling of backgrounds and new pp reference) At midrapidity, less subjective “onset” like shape… y~1.7 y~0 37/29

2007, July 16th Quarkonia from SPS to RHIC - Nuclear absorption only Compute L with Glauber model Fit exp(-σ abs ρ 0 L) Results are different wrt KKS numbers KKS, PLB637(2006)75 38/29

2007, July 16th Quarkonia from SPS to RHIC - Feed down ratio’s ? From HERA-B (pA √s=41.6 GeV) –7.0 ± 0.4 % from ψ’ –21 ± 5 % from χ c –0.065 ± % from B Faccioli, Hard Probes /29

Rescaling survival probabilities… 2007, July 16th Quarkonia from SPS to RHIC - x ≈1.2 x ≈1.5 R dA rescaled by run5pp, different systematics, wait for PHENIX reanalysis ! 40/29

2007, July 16th Quarkonia from SPS to RHIC - Cold nuclear matter effects ? open charm dE/dx ? Intrinsic Charm ? Shadowing ? Absorption ? σ ψ (pA) = σ ψ (pp) x A  = x p - x A = x A A real puzzle ! Especially when one goes to low x 2, high x F … 41/29

2007, July 16th Quarkonia from SPS to RHIC - R dA R dAu vs RHIC Data favours –(weak) shadowing Eskola, Kolhinen, Salgado prescription matches better –(weak) absorption σ abs ~ 1 to 3 mb ! (4.18 ± 0.35 But with limited statistics difficult to disentangle nuclear effects ! PHENIX, PRL96 (2006) Klein,Vogt, PRL91 (2003) Kopeliovich, NPA696 (2001) 669 Low x 2 ~ (shadowing region) 42/29

2007, July 16th Quarkonia from SPS to RHIC - How to get x F scaling ? 43/29

2007, July 16th Quarkonia from SPS to RHIC - Tuchin & Kharzeev Hard probes 2004 –hep-ph/ Coherent production of charm (open or closed) –(y<0 production time to low to make computation) –Shadowing from CGC computation… Tuchin 44/29

2007, July 16th Quarkonia from SPS to RHIC - Tuchin & Kharzeev… + absorption for SPS & fermilab 45/29