Quarkonium suppression from SPS to RHIC

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(and from pA to AA). Quarkonium suppression from SPS to RHIC. Raphaël Granier de Cassagnac LLR – École polytechnique / IN2P3 Hard Probes 2006 Asilomar, California, June 13 th. Normal suppression. Anomalous Suppression ?. Energy density ?. Are we there yet ?. J/ ψ survival - PowerPoint PPT Presentation

Transcript of Quarkonium suppression from SPS to RHIC

  • Quarkonium suppression from SPS to RHIC

    Raphal Granier de CassagnacLLR cole polytechnique / IN2P3

    Hard Probes 2006Asilomar, California, June 13th

    (and from pA to AA)

    Quarkonium at SPS & RHIC - [email protected]

  • Are we there yet ?Energydensity ?J/ survival probability ?

    Quarkonium at SPS & RHIC - [email protected]

  • A couple of historical factsIn 1986, Matsui & Satz (happy birthday Helmut) predicted an unambiguous signature of QGP, that was immediately (1992) seen by NA38 in SU collisionsNA38, NPA544 (1992) 209Matsui & Satz, PLB178 (1986) 416

    Quarkonium at SPS & RHIC - [email protected]

  • First, beware of cold nuclear matter effects !

    Quarkonium at SPS & RHIC - [email protected]

  • Cold nuclear matter effects ?J/ (or cc) absorption(Anti) shadowing(gluon saturation, CGC)Energy loss of initial partonpT broadening (Cronin effect)Complications from feeddown & c ?Something else ?gluons in Pb / gluons in pxEskola, Kolhinen, VogtNPA696 (2001) 729An example of gluon shadowing predictionAntiShadowingShadowing

    Quarkonium at SPS & RHIC - [email protected]

  • Cold nuclear matter effects ?open charmdE/dx ?IntrinsicCharm ?Shadowing ?Absorption ?(pA) = (pp) x A = xp- xA = xAA real puzzle ! Especially when one goes to low x2, high xFSee Ming Liu,Kirill Tuchin,Ivan Vitevin this meeting

    Quarkonium at SPS & RHIC - [email protected]

  • Nobody is [email protected]: many pA ! High statistics ! But small kinematics (-0.1 < xF < 0.1)Nuclear absorption does a splendid [email protected]: less pA High statistics ! Large rapidity (xF) coverage No AAMany cold nuclear effects needed [email protected]: only dAu, low statistics, but rapidity (-2.2 to 2.2) and centrality dependenceAbsorption + (anti)shadowing

    Quarkonium at SPS & RHIC - [email protected]

  • Cold nuclear matter @ SPSNormal nuclear absorption does a splendid job in describing pA, SU, peripheral Pb-Pb(1992 SU suppression was normal)exp(-abs L) with L nuclear thickness &abs = 4,18 0,35 mbNA50, EPJ C39 (2005) 335

    Quarkonium at SPS & RHIC - [email protected]

  • From pA to AACold nuclear matter extrapolations always rely on some models and pA data with various balance between the two

    @SPS, plug measured nuclear absorption either as exp(- L) or in Glauber modelIs there room for (anti)shadowing ?Is the pA absorption applicable to AA ? absorption differs ! (7.9 0.6 mb)And feed down ratios may change in AA !Not taken care of, but again, absorption does a splendid job from pp to peripheral Pb-Pb

    Quarkonium at SPS & RHIC - [email protected]

  • RdAu vs Ncoll @ RHICFirst centrality dependence in dA (or pA) measurementColored lines:FGS shadowing for 3 mbBlack lines:EKS98 shadowing+ abs = 0 to 3 mbTogether with rapidity shape, this favours EKS98 + moderate absorptionHigh x2 ~ 0.09Low x2 ~ 0.003RdA

    Quarkonium at SPS & RHIC - [email protected]

  • RdAu vs rapidity @ RHICData favours (weak) shadowingEskola, Kolhinen, Salgado prescription matches better(weak) absorption abs ~ 1 to 3 mb !(4.18 0.35 mb @SPS)But with limited statistics difficult to disentangle nuclear effects !RdAPHENIX, PRL96 (2006) 012304Klein,Vogt, PRL91 (2003) 142301Kopeliovich, NPA696 (2001) 669

    Quarkonium at SPS & RHIC - [email protected]

  • From dA to AA @ RHICWhat is on the market ? First, the dA data are poorA model of nuclear absorption + (anti)shadowing (Ramona Vogt, nucl-th/0507027)exp -(diss(y)+diss(-y))n0L (Karsch, Kharzeev & Satz PLB637(2006)75)diss from fits on dA data But shadowing doesnt go like L My own toy model (next 3 slides)

    Quarkonium at SPS & RHIC - [email protected]

  • My own toy model (1/3)Data driven, as much as possiblePhenomenological fit to RdA(b) Plug this in AuAu Glauber: RAA(y,bAA) = collisions [ RdA(-y,b1) x RdA (y,b2) ]Works for absorption & shadowing since: production ~ pdf1 x pdf2 x exp n(L1+L2)Y = -1.7Y = 0Y = 1.8RdAb(fm)

    Quarkonium at SPS & RHIC - [email protected]

  • My own toy model (2/3)Bands are statistical and systematic errors from dAu No systematics from the method itself (work in progress)Average on AuAu centrality classes to compare to data

    Quarkonium at SPS & RHIC - [email protected]

  • My own toy model (3/3)Comparison to AuAu data and Ramonas model

    Quarkonium at SPS & RHIC - [email protected]

  • Then Whats going on with the anomalous suppression ?

    Quarkonium at SPS & RHIC - [email protected]

  • Whats going on @SPS ?Several models could fit NA50Plasma (either thermal or percolative)Comovers (hadronic or partonic ?)Now NA60 Difficult to reproduceRoberta Arnaldi, QM05+ new analysis, this meeting

    Quarkonium at SPS & RHIC - [email protected]

  • Whats going on @ RHIC ?Shadowing + nuclear absorption (crucial !)PHENIX, QM05, nucl-ex/0510051 + Abigail Bickley, this meetingVogt, nucl-th/0507027Error bar code : bars = statistical, bracket = systematic, box : global.1.2 < |y| < 2.2 -0.35 < y < 0.35

    Quarkonium at SPS & RHIC - [email protected]

  • NA50 only effectsCold effects + Comovers (hadrons or partons?)Kinetic model (J/ c c )Thermal plasmaAll overestimate suppression !So does parton percolationOnset at Npart ~ 90 Simultaneous J/ + c + Capella, Ferreiro, EPJC42 (2005) 419Grandchamp et al, PRL92 (2004) 212301 Kotstyuk et al, PRC68 (2003) 041902 Digal, Fortuno, Satz, EPJC32 (2004) 547 + Private communications +(AuAu only)

    Quarkonium at SPS & RHIC - [email protected]

  • 1st. Recombination ?A variety of recombination & coalescence models can accommodate the suppression

    But early results suggest some competing mechanism, such as reformation of J/ particles, may occur at these densities. Riordan & Zajc, Scientific American

    To know more, look at y, pTGrandchamp et al, PRL92 (2004) 212301 Bratkoskaya et al, PRC69 (2004) 054903Andronic et al, PLB571 (2003) 36Thews & Mangano, PRC73 (2006) 014904c + Private communications +(AuAu only)

    Quarkonium at SPS & RHIC - [email protected]

  • y shape (vs recombination)Recombination emphasizes quark y-distributionQuark (open charm) y-distribution unknown No significant change in rapidity in dataRecombined only ! Thews & Mangano, PRC73 (2006) 014904c

    Quarkonium at SPS & RHIC - [email protected]

  • (vs Cronin effect)AA = pp + pT2 x L [nuclear matter thickness](random walk of initial gluons)

    VN Tram, Moriond 2006 & PhD thesisLower energy surveypp, pA and AA

    Quarkonium at SPS & RHIC - [email protected]

  • Cronin versus recombinationAt forward rapidity (closed symbols)from pp & dA: = 2.51 + 0.32 L (L Ncoll conversion)No sign of recombination !At mid rapidity (open symbols)Negligible Cronin !?...Need better pp !

    VN Tram, Moriond 2006 & PhD thesisSee Bob Thews talk tomorrow !p+p d+Au Au+AuOpen symbol: y ~ 0Full & curves: y ~ 2 = 2.51 + 0.32 L

    Quarkonium at SPS & RHIC - [email protected]

  • 2nd. Hydro + J/ transportOne detailed QGP hydro + J/ transport (Zhu et al)g + J/ c + cFirst published without cold nuclear effects, but here :+ Nuclear absorption (1 or 3 mb)+ Cronin effect from dAu ok (as on previous slide)

    Model should be valid for y=0But match y=1.7 (and central y=0)Zhu, Zhuang, Xu, PLB607 (2005) 107+ private communicationPredicted RAA for y=0

    Quarkonium at SPS & RHIC - [email protected]

  • 3rd (simple) explanationAmount of anomalous suppression depends on cold nuclear effects amplitudeBut could be as low as 30 to 40%Compatible to feed-down ratioJ/ ~ 0.6 J/ + 0.3 c + 0.1 Recent lattice Td ~ 1.5 - 2.5 Tc x (TdJ/ ~ 2Tc)4 = 2 c dJ/ ~ 32 c !Wait for LHC to melt J/ ?

    Quarkonium at SPS & RHIC - [email protected]

  • Back to SPS + RHICSequential melting scenarioJ/ survival onlyExcited states melting from suppression pattern @ SPSBe careful when showing this!NA60 and PHENIX are PRELMINARYNo systematic uncertainties on PHENIX points(see Abigail Bickleys)No uncertainties from cold nuclear matter effectsHowever, it does a good job and sequential melting clearly is a possibility !...Karsch, Kharzeev & SatzPLB637(2006)75???

    Quarkonium at SPS & RHIC - [email protected]

  • Now, can we plot everybody together ?

    Quarkonium at SPS & RHIC - [email protected]

  • x-axis : energy density ?Should be the right variableBut we really dont know how to compare RHIC & SPS !0 > 1 fm/c @ SPS(nuclei take 1.6 fm/c to cross each other)0 < 1 fm/c @ RHIC(formation time ~ 0.35 ?thermalization ~ 0.6 to 1 ?)All RHICAll SPS

    Quarkonium at SPS & RHIC - [email protected]

  • Thats it for today NA60 new points from Roberta Arnaldi RHIC for 3mb normal absorptionRHIC for 1mb normal absorption(global SPS uncertainty not included)

    Quarkonium at SPS & RHIC - [email protected]

  • Anomalous conclusionsFor now, no model to explain NA60:But maybe sequential melting ?For now, 3 models to explain RHIC:1st Recombination ?But no sign of y or pT2 modificationsJ/ (Ncc)2 (but how much is Ncc ?)2nd J/ detailed transport in hydro QGP3rd Sequential melting ?J/ may still survive @ RHIC(this three models assume a QGP)

    Quarkonium at SPS & RHIC - [email protected]

  • The show must go onWhat is coming from SPS ?J/ flow (Cf. Francesco Prino tomorrow) from InIn ? c from pA ?J/ pA @ 158 AGeV

    What is coming from RHIC ?Final AA analysis A bit more data & more bins !With a bett