Lecture 2 on J/ ï¹ suppression

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Michel GONIN. Lecture 2 on J/  suppression. 1. Charmonium bound states. 2. Screening effects in the plasma. 3. Experimental results. 4. Life (for physicist) is tough. l D depends on the temperature. . quarkonia. q. q. Lattice QCD.  ’. . T > T c. .  = 0. - PowerPoint PPT Presentation

Transcript of Lecture 2 on J/ ï¹ suppression

  • Lecture 2 on J/ suppression1. Charmonium bound states2. Screening effects in the plasma 3. Experimental results 4. Life (for physicist) is tough

  • lD depends on the temperature

  • Satz et al.Successive (vs. temperature) melting for the quarkonia Signals for the Deconfinement

  • Satz et al.13245Suppression Quakonia ScreeningBounding Energy (MeV)Screening Temperature Energy density (GeV/fm3)

    40Tc 1.0 240Tc 1.0 6701.4 Tc 3.8 6401.4 Tc 3.8 11003.2 Tc 100

  • NA50 at CERNElectromagnetic desintegrationcc

  • J/ e+e identified in RICH and EMCal|| < 0.35 p > 0.2 GeV

    J/+ identified in 2 fwd spectrometers1.2 < || < 2.4p > 2 GeV

    How does PHENIX see the J/ ?

  • Cathode-strip chambers = 24000 voies analogiques / brasPistes = 1cms (barycentre) = 100mmBruit/Signal ~ 1% ADC 11 bits, 4 chantillons temporels 100 ns

  • d-Au sampleMass Resolution ~ 100 MeVDi-electron analysisDi-muons analysisMass Resolution ~ 150 MeV

  • NA50 at CERN

  • Short history of RHIC

  • NA50Ordinary absorptionANOMALOUSJ/SUPPRESSION

  • EZDC (GeV)Beam

  • Satz et al.Suppression

  • Satz et al.Suppression13245 NA50

  • Satz et al.Suppression13245

  • DECONFINEMENT !!!Heavy Ion PhysicsHigh Energy Physics

  • Life is tough

  • not exactely

    40Tc 1.0 240Tc 1.0 6701.4 Tc 3.8 6401.4 Tc 3.8 11003.2 Tc 100

  • t = 0 J/ J/10 fm/c t 20 fm/c - Screening effects- hard gluon scatteringDeconfinement WITH PLASMAHadronizationc c t 2 fm/c mixed phasec d c d Hadronic gasFreeze-outD D t 5 fm/c c c

  • Regeneration : answer from RHIC R.RappS-UPb-Pb

  • Satz et al.Suppression13245

  • Life is tough

  • J/ + protons (neutrons) open charm CHARMONIA DISSOCIATIONJ/p

  • Glauber absorption model Rarely produced (no multi-production) Uniforme (inside the nucleus) production probability Short ( 1fm/c) formation time straight line trajectories

  • Does it work ??Yes

  • J/

  • Glauber absorption model

  • Glauber absorption model

  • antiprotonCERN : abs. = 21.4 2 mbBNL : abs. = 24.8 3 5 mb

  • Glauber absorption modelDrell-Yanno absorption abs. 0

  • J/

  • J/

  • Ordinary dissociationp-A p-p

  • Life is tough

  • t = 0 10 fm/c t 20 fm/c - Screening effects- hard gluon scatteringDeconfinement WITH PLASMAHadronizationc c t 2 fm/c mixed phasec d c d Hadronic gasFreeze-outD D t 5 fm/c c c

  • t = 0 0.3 fm/c t 0.9 fm/c J/c c 1.5 fm/c t 2 fm/c 10 fm/c t 20 fm/c c c + nucleons J/ + nucleons J/ + ,,,Nucleons ComoversWITHOUT PLASMAproduced hadronsFreeze-out

  • Failure of the comover calculations to reproduce the data

  • Failure of the comover calculations to reproduce the dataGale et al.

  • ComoversUrQMD

  • Wong et al.

  • A. Capella

  • Failure of the comover calculations to reproduce the data

  • 2003 The comover calculations to reproduce the data CapellaCassingS+U

  • Capella 2002Capella 1998 the comover calculations can reproduce the data

  • the comover calculations to reproduce the data 2002

  • the comover calculations to reproduce the data 2002THE COST

  • the comover calculations to reproduce the data 2002THE COSTncomv 1 / fm3Cassing et al

  • Life is tough

  • Structure functions of the proton or neutronF(x) F(x,Q2) for low Q2 (QCD non-perturbative)

  • gluonsInside a proton .

  • xgluon m (m)/sxgluon = fraction of total momentum

  • Gluon shadowing dans A = 208Gluons distribution inside the nucleus ??xgxgEskola et al.Structure fonctionsratio pp/pA

  • RHICCERNxLHC

  • Deuteron Gold In PHENIX, J/ mostly produced by gluon fusion, and thus sensitive to gluon pdf

    Three rapidity ranges probe different momentum fraction of Au partonsSouth (y < -1.2) : large X2 (in gold) ~ 0.090Central (y ~ 0) : intermediate X2 ~ 0.020North (y > 1.2) : small X2 (in gold) ~ 0.003dAu

  • Broadening comparable to lower energy (s = 39 GeV in E866)Low x2High x2RdA

  • Total cross section (preliminary)BR pp = 159 nb 8.5 % (fit) 12.3% (abs)

    J

  • Data favours (weak) shadowingLow x2 ~ 0.003(shadowing region)+ (weak) absorption ( > 0.92)With limited statistics difficult to disentangle nuclear effectsRdA

  • Not universal versus X2 : shadowing is not the whole story.Same versus XF for diff s. Incident parton energy loss ? (high Xd = high XF)Energy loss expected to be weak at RHIC energy.X2 (in gold)E866: PRL 84, 3256 (2000) NA3: ZP C20, 101 (1983)

  • NA50Ordinary absorptionANOMALOUSJ/SUPPRESSION