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Quark Matter at RHIC II

Quark Matter at RHIC II. higher luminosity + detector upgrades → how does this new plasma work?. Barbara Jacak Stony Brook. Kolb, et al. PHENIX. RHIC creates fundamentally new matter. Pressure built up very rapidly during ion collisions at RHIC large collective flow, calculate w/hydro

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Quark Matter at RHIC II

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  1. Quark Matter at RHIC II higher luminosity + detector upgrades → how does this new plasma work? Barbara Jacak Stony Brook

  2. Kolb, et al PHENIX RHIC creates fundamentally new matter • Pressure built up very rapidly during ion collisions at RHIC • large collective flow, calculate w/hydro • viscosity small, interaction s large, • thermalization is fast • huge energy loss by fast quarks traversing medium • medium is opaque • large energy & gluon density • baryon production enhanced by • factor of 3 compared to p+p Barbara Jacak Quark Matter 2006

  3. plasma • ionized but macroscopically neutral • exhibit collective effects interactions among charges of multiple particles • spreads charge out into characteristic (Debye) length, lD • >1 particles inside this length, screen each other • “normal” plasmas: EM interaction • can vary r, T independently • photon p, e usually irrelevant • can be strongly or weakly coupled • QCD plasma • T determines all properties (heavy q mass sets new scale) • intrinsically strongly coupled for accessible T • quarks & gluons NOT asymptotically “free to roam” • …not your mother’s plasma… Barbara Jacak Quark Matter 2006

  4. Compelling reasons for higher luminosity* * and upgrading STAR, PHENIX • Entirely new questions posed by RHIC • fast thermalization mechanism? • how low is the viscosity of the liquid? • response of plasma to deposited energy? • what is the color screening length? • is the initial state a color glass condensate? • Early questions still unresolved • nature of phase transition? critical point? • equation of state of hot QCD matter? • do dilepton observables provide evidence for chiral symmetry restoration? Barbara Jacak Quark Matter 2006

  5. RHIC and the phase transition • lattice says: collisions at RHIC map interesting region Tinit ~ 300 MeV Tfinal ~ 100 MeV Recall per massless degree of freedom Barbara Jacak Quark Matter 2006

  6. There is some space left! STAR PHENIX Barbara Jacak Quark Matter 2006

  7. NCC NCC HBD MPC MPC VTX & FVTX Upgraded PHENIX Acceptance EMCAL 0 f coverage 2p EMCAL -3 -2 -1 0 1 2 3 rapidity (i) p0 and direct g with combination of all electromagnetic calorimeters (ii) heavy flavor with precision vertex tracking with silicon detectors combine (i)&(ii) for jet tomography with g-jet (iii) low mass dilepton measurments with HBD + PHENIX central arms Barbara Jacak Quark Matter 2006

  8. Full Barrel Time-of-Flight system Forward Meson Spectrometer Forward triple-GEM EEMC tracker STAR Upgrades DAQ and TPC-FEE upgrade Integrated Tracking Upgrade Forward silicon tracker HFT pixel detector Barrel silicon tracker Barbara Jacak Quark Matter 2006

  9. STAR TPC performance Barbara Jacak Quark Matter 2006

  10. Long term facility strategy Barbara Jacak Quark Matter 2006

  11. answering the questions with RHIC II • First things first • phase transition study and EOS • medium modification of mesons & chiral symmetry • experiment • energy scan • precision measurement of particle flow & dileptons • flow of more massive probes • also probe thermalization, diffusion and viscosity • theory • hydro simulations to quantify parameter dep. of flow • can the relationship of dileptons and chiral symmetry be put onto firm theoretical footing? Barbara Jacak Quark Matter 2006

  12. need to measure T directly! • Temperature via blackbody radiation • real & virtual g • as a function of e, m • e+e- also signal any late stage medium modification of hadrons huge backgrounds below 1.5 GeV mass or Eg detector upgrades to reject decays & measure charm Barbara Jacak Quark Matter 2006

  13. Kolb, et al Equation of State (also viscosity probe) • map p vs. e as a function of collision energy, system size • measure c, W, X, f flows • improve hydro, upgrade PID capabilities • p = e /3 for ideal QGP resonance gas p > e /3 • generate pressure • rather than make • more resonances • energy scan to search for • critical point on phase diagram Barbara Jacak Quark Matter 2006

  14. PLB595(2004)202 heavy hadron flow figure of merit • pT range of identified hadron v2 • especially p, L, W • D, B meson flow PHENIX SiVX, RHIC I Barbara Jacak Quark Matter 2006 STAR, ALICE?

  15. RHIC Heavy Ion Collisions Expected whole vertex minbias event rate [Hz] T. Roser, T. Satogata Dileptons & chiral symmetry restoration? • Search for critical point  bulk hadron production and fluctuations • Requires moderate luminosity • do-able in next few years? • Chiral symmetry restoration  dilepton production • Requires upgraded luminosity • With electron cooling: • 4 weeks run, 25% recording eff. electron trigger • √s = 20 GeV  109 events • 2 GeV 107 events • CERES ~ 4x107, • NA60 sampled ~ 1010 In+In Increase by factor 100 with electron cooling Barbara Jacak Quark Matter 2006

  16. Simulations Counts (K++K-)/(++-) critical point search Barbara Jacak Quark Matter 2006

  17. dilepton figure of merit modify along with previous slide • statistical precision of r,w,f mass measurements • pT reach of spectra • continuum between r & f + Barbara Jacak Quark Matter 2006

  18. Now to the new questions • thermalization mechanism? • probe elastic scattering via heavy quark v2 and RAA • plasma instability? • what is the color screening length? • response of plasma to deposited energy? • is the initial state a color glass condensate? Barbara Jacak Quark Matter 2006

  19. role of B decays in electron RAAandv2 ? • need RHIC II luminosity & deterctor upgrades • direct probe of extent & timescale of thermalization? • RHIC II will yield • statistics for v2, pT reach for heavy quarks • allow scan of systems with exclusive decay channels • relative abundance of charmed hadron states inner trackers for PHENIX and STAR Barbara Jacak Quark Matter 2006

  20. RHIC II luminosity will sort it out from Tony Frawley RHIC Users mtg. Barbara Jacak Quark Matter 2006

  21. Karsch, Kharzeev, Satz, hep-ph/0512239 40% of J/y from c and y’ decays they are screened but direct J/y not? screening length: onium spectroscopy Barbara Jacak Quark Matter 2006

  22. Transport properties transport in plasmas is driven by collisions • transport of particles → diffusion • transport of energy by particles → thermal conductivity • transport of momentum by particles → viscosity • transport of charge by particles → electrical conductivity • is transport of color charge an analogous question for us? Barbara Jacak Quark Matter 2006

  23. from <r> to r(x,v): Jet tomography • as a function of system size, energy • → parton & energy density gives EOS • → vary pT to probe medium coupling, • see early development of system • golden channel: g-jet correlations • g fixes jet energy • flavor-tagged jets to sort out g vs. q energy loss • detector upgrades → coverage • luminosity & DAQ upgrades→ rate Barbara Jacak Quark Matter 2006

  24. events per year Barbara Jacak Quark Matter 2006

  25. PHENIX nucl-ex/0507004 dN/d(Df) STAR PRL95, 152301 (2005) (1/Ntrig)dN/d(Df) M.Miller, QM04 0 p/2 p p/2 p Df challenge: can a jet excite a density wave in the plasma? need to update g radiates energy kick particles in the plasma accelerate them along the jet non-equilibrium process Barbara Jacak Quark Matter 2006

  26. shear generally a phenomenon in crystals but not liquids Barbara Jacak Quark Matter 2006

  27. minimum h at phase boundary? seen in strongly coupled dusty plasma B. Liu and J. Goree, cond-mat/0502009 Csernai, Kapusta & McLerran nucl-th/0604032 minimum arises because kinetic part of h decreases with G & potential part increases; measure by density-density correlation Barbara Jacak Quark Matter 2006

  28. d+Au Δ2 Au+Au Central 0-12% Triggered Δ1 Δ1 3 particle correlations support cone-like structure pT = 3-4  1-2 GeV/c Need a LOT more statistics to pin down pT ,centrality (&T) dependence of >2 particle correlations! J. Ulery, HP06 Barbara Jacak Quark Matter 2006

  29. g-h and g-h-h events per year still working on plot Barbara Jacak Quark Matter 2006

  30. D. Morrison, SQM’06 other key measurements at RHIC II • elliptic flow at high pT • g elliptic flow • g HBT • map baryon & multi-strange • hadron production • poke at the hadronization • mechanism • probe 2q correlations • in the medium all have large backgrounds require RHIC II luminosity & detector upgrades to reject background & probe as a function of e, m Barbara Jacak Quark Matter 2006

  31. RHIC II will get us • from “oh wow!” • we have found a surprising new form of matter • to “aha!” • here is how it works • how QGP relates to and helps progress in other fields Barbara Jacak Quark Matter 2006

  32. backup slides Barbara Jacak Quark Matter 2006

  33. Plasma properties we will measure at RHIC II Barbara Jacak Quark Matter 2006

  34. to explore at RHIC II ≥ 2014 Barbara Jacak Quark Matter 2006

  35. use this technique to measure viscosity melt crystal with laser light induce a shear flow (laminar) image the dust to get velocity study: spatial profiles vx(y) moments, fluctuations → T(x,y) curvature of velocity profile → drag forces viscous transport of drag in  direction from laser compare to viscous hydro. extract h/r shear viscosity/mass density PE vs. KE competition governs coupling & phase of matter Csernai,Kapusta,McLerran nucl-th/0604032 Barbara Jacak Quark Matter 2006

  36. Hatsuda, et al. Lattice QCD shows qq resonant states at T > Tc, also implying high interaction cross sections Fast equilibration, highopacity (even for charm): how? Molnar multiple collisions using free q,g scattering cross sections doesn’t work! need s x50 in the medium Barbara Jacak Quark Matter 2006

  37. proton pion Temperature: hydro, eloss say 380-400 MeV nucl-ex/0410003 Hydro models: Teaney (w/ & w/o RQMD) Hirano (3d) Kolb Huovinen (w/& w/o QGP) Barbara Jacak Quark Matter 2006

  38. strong elliptic flow, scales w/ number of quarks Barbara Jacak Quark Matter 2006

  39. Plasmas exhibit screening • Debye length: distance where influence of an individual charged particle is felt by the other particles in the plasma • charged particles arrange themselves so as to effectively shield any electrostatic fields within a distance lD • lD = e0kT • ------- • nee2 • Debye sphere = sphere with radius lD • number electrons inside Debye sphere is typically large • ND= N/VD= rVD VD= 4/3 plD3 1/2 in strongly coupled plasmas it’s  1 Barbara Jacak Quark Matter 2006

  40. Debye screening in QCD: a tricky concept • in leading order QCD (O. Philipsen, hep-ph/0010327) • vv Barbara Jacak Quark Matter 2006

  41. don’t give up! ask lattice QCD Karsch, et al. running coupling coupling drops off for r > 0.3 fm Barbara Jacak Quark Matter 2006

  42. screening masses from gluon propagator Screening mass, mD, defines inverse length scale Inside this distance, an equilibrated plasma is sensitive to insertion of a static source Outside it’s not. Nakamura, Saito & Sakai, hep-lat/0311024 T dependence of electric & magnetic screening masses Quenched lattice study of gluon propagator figure shows: mD,m= 3Tc, mD,e= 6Tc at 2Tc lD ~ 0.4 & 0.2 fm magnetic screening mass is non-zero not very gauge-dependent, but DOES grow w/ lattice size (long range is important) Barbara Jacak Quark Matter 2006

  43. Implications of lD ~ 0.3 fm • can use to estimate Coupling parameter, G • G = <PE>/<KE> but also G = 1/ND • for lD = 0.3fm and e = 15 GeV/fm3 • VD = 4/3 plD3 = 0.113 fm3 • ED = 1.7 GeV • to convert to number of particles, use gT or g2T • for T ~ 2Tc and g2 = 4 • get ND = 1.2 – 2.5  G ~ 1 • NB: for G ~ 1 • plasma is NOT fully screened – it’s strongly coupled! • affects interaction s! • other strongly coupled plasmas behave as liquids, even crystals for G≥ 150 • dusty plasmas, cold atoms+ions , warm dense matter Barbara Jacak Quark Matter 2006

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