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The Future of Quark Matter at RHIC. higher luminosity + detector upgrades → how does this new plasma work?. Barbara Jacak Stony Brook. Compelling reasons for higher luminosity*. * and upgrading STAR, PHENIX. Entirely new questions posed by RHIC fast thermalization mechanism?
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The Future of Quark Matter at RHIC higher luminosity + detector upgrades → how does this new plasma work? Barbara Jacak Stony Brook
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 the plasma to deposited energy? • what is the color screening length? • is the initial state a color glass condensate? • Early questions still outstanding • nature of phase transition? critical point? • equation of state of hot QCD matter? • do heavy quark bound states melt? • can dilepton observables provide evidence for chiral symmetry restoration? Barbara Jacak QM06
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 QM06
There is some space left! STAR PHENIX Barbara Jacak QM06
Full Barrel Time-of-Flight system Forward Meson Spectrom. Forward triple-GEM EEMC tracker STAR Upgrades DAQ and TPC-FEE upgrade light hadron flow initial state heavy flavor Integrated Tracking Upgrade Forward silicon tracker HFT pixel detector Barrel silicon tracker Barbara Jacak QM06
STAR TPC performance at high luminosity fall 2006 review report • distortion effects from space charge in TPC successfully corrected (to level of 100-200 mm) • procedures to tackle event pileup demonstrated in p+p and Cu+Cu collisions • expected to be successful also at higher luminosities • faster readout electronics part of DAQ upgrade PHENIX detectors, trigger and DAQ designed for high rate Barbara Jacak QM06
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 additional EM calorimeters (NCC, MPC) (ii) heavy flavor with silicon vertex tracker (VTX, FVTX) (i)+(ii) for large acceptance g-jet (iii) low mass dileptons (HBD) Barbara Jacak QM06
RHIC II • electron cooling • L x10 • low energy run • possible now • # steps increased by cooling • ~30% higher e with U+U • feasible with EBIS • higher v2 sensitivity • (if geometry controllable) • better constrain hydro • central nose-on collisions • rare – aided by higher L Expected whole vertex minbias event rate [Hz] Barbara Jacak QM06 T. Roser, T. Satogata
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 the plasma to deposited energy? • what is the color screening length? • is the initial state a color glass condensate? • Early questions still outstanding • nature of phase transition? critical point? • equation of state of hot QCD matter? • do heavy quark bound states melt? • can dilepton observables provide evidence for chiral symmetry restoration? Barbara Jacak QM06
STAR preliminary non-photonic single electrons how to measure viscosity and EOS? radial, directed & elliptic flow mass dependence of flow ↔ EOS ideal QGP: p = e /3 resonance gas: p > e /3 multistrange hadron W, X, f v2 → late stage dissipation vs.early viscosity heavy meson v2→ tthermalization, h/s compare to viscous 3D hydro does h/S vary with Ebeam? alsofluctuations and g & g* for precision science: scan energy & system size Barbara Jacak QM06
PHENIX SiVX, RHIC II Detector upgrades to improve PID v2 PHENIX SiVX, RHIC I vertex detector → D, B meson flow identified W v2 with TOF barrel RHIC II allows energy scan Barbara Jacak QM06
urgently need theory homework! • how to solve relativistic viscous hydrodynamics? • both theory and phenomenology • implement in 3D, vary parameters for data comparison • charm & strangeness v2 to probe limitations of hydro • improve pT reach • viscosity: an average quantity • pick apart momentum transport by different particles? • but this cannot be at the expense of fundamental theory! • understand the initial state (CGC→ glasma→ plasma) • thermalization? observables of instabilities • pre-equilibrium matter dynamics (e.g. molecular dynamics) Barbara Jacak QM06
where is the QCD critical point? energy scan up to mB ~ 500 MeV RHIC II L will make this faster, allowing finer steps STAR Barbara Jacak QM06
Compelling reasons for higher luminosity • Entirely new questions posed by RHIC • fast thermalization mechanism? • how low is the viscosity of the liquid? • response of the plasma to deposited energy? • what is the color screening length? • is the initial state a color glass condensate? Barbara Jacak QM06
Need better statistics at high pT from J. Lajoie talk C. Loizides hep-ph/0608133v2 Barbara Jacak QM06
Transport and extracting parameters from data • 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 • how is color charge transported? • for precision science need substantial progress in theory • transport in medium where coupling is not weak • can J.P. Blaizot do this with resummation??? • scattering of particles from color fields (coherent?) • NLO calculation of energy loss in expanding medium • precise calculation of collective excitation observables Barbara Jacak QM06
golden channel: g-jet probe medium: precision correlations w/few GeV h 3-particle correlation: jet-jet at RHIC II: 5Kp0, 10K direct g (pT ≥ 20 GeV) 7Kg-h in PHENIX 80K 20 GeV g-h and 5K 10GeV g + 2h(≥4 GeV) in ±1 unit y Barbara Jacak QM06
but wait, this is LHC territory! • RHIC II flexibility and integrated luminosity makes it a very exciting place to be! • Two basic regions: • hard-hard correlations to study energy loss • Majumder:10-20 GeV jet, fragment pT ≥ 5 GeV/c • hard-soft(ish) correlations for medium response • fragment pT = 1-4 GeV/c • let’s take a look at annual yields of events Barbara Jacak QM06
events per year p0 suppression at RHIC & LHC W.Vogelsang NLO RHIC II L= 20nb-1 LHC: 1 month run NB: large g/p0 at RHIC → direct g is ideal probe! Barbara Jacak QM06
events per year: ≥10 GeV g + 2h (pT > pT,min) STAR & upgraded PHENIX Many 3 particle coincidence events (pT>pT,reco)! Full jet reconstruction may be feasible Jet energies lower than LHC… Barbara Jacak QM06
but 10-20 GeV is where the medium action is! STAR nucl-ex/0604018 Majumder, et al. hep-ph/0611135 pT trigger > 8 GeV/c energy loss by 20 GeV jets accessible at RHIC (& interpretable) Barbara Jacak QM06
Compelling reasons for higher luminosity • Entirely new questions posed by RHIC • fast thermalization mechanism? • how low is the viscosity of the liquid? • response of the plasma to deposited energy? • what is the color screening length? • is the initial state a color glass condensate? • Early questions still outstanding • nature of phase transition? critical point? • equation of state of hot QCD matter? • do heavy quark bound states melt? Barbara Jacak QM06
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 QM06
STAR Prelim. p+p 200 GeV e+e- Minv how to do better? • improve precision of data • larger pT reach • extend measurement to heavier states • theory effort needed • disentangle (miraculously) cancelling processes! • calculations including: CGC + screening + regeneration • in an expanding medium • study cc coupling to medium & impact on bound state • quantitative QCD developments beyond static lattice Barbara Jacak QM06
Annual yields at RHIC II & LHC from Tony Frawley RHIC Users mtg. at LHC: (10-50) x s ~10% of L 25% running time Barbara Jacak QM06
Long term RHIC facility strategy Barbara Jacak QM06
Compelling reasons for higher luminosity * could motivate new experiment • Entirely new questions posed by RHIC • fast thermalization mechanism? * • how low is the viscosity of the liquid? • response of the plasma to deposited energy? * • what is the color screening length? • is the initial state a color glass condensate? * • Early questions still outstanding • nature of phase transition? critical point? • equation of state of hot QCD matter? • do heavy quark bound states melt? • can dilepton observables provide evidence for chiral symmetry restoration? Barbara Jacak QM06
Relevance to Heavy Ion Collisions from B. Zajc DNP • Collisions at RHICefficiently translate initial gluon state • strong shadowing? • saturated gluons? • Color Glass Condensate? • to final thermal state • Difficult to understand this efficiency without some form of dense gluonic initial state • We would rather measure than invoke • An electron-Ion collider Barbara Jacak QM06
backup slides Barbara Jacak QM06
Preliminary high luminosity energy scan map energy loss and medium response as function of T, mB Barbara Jacak QM06
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 QM06
A method to extract viscosity • Paul Stankus viscosity is a dissipative effect drive local equilibrium towards global equilibrium. So higher viscosity means lower v2, and also lower v3, v4, etc. (v1 is a special case, since it obeys a sum rule). v3 v2 • Colliding asymmetric systems will allow us access to odd values of vn • Is v3 more sensitive than v2 to viscosity? • Need A+B running with statistics comparable to Run4/5 • Takes advantage of RHIC flexibility & luminosity (feasible at LHC?) • Currently work on 3-D hydro and hydro+viscosity • Need to combine Hydro with cascade with Reco Barbara Jacak QM06
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 QM06
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 QM06
Plasma properties we will measure at RHIC II Barbara Jacak QM06
to explore at RHIC II ≥ 2014 Barbara Jacak QM06
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 QM06
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 QM06
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 QM06
shear generally a phenomenon in crystals but not liquids Barbara Jacak QM06
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 QM06
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 QM06
Debye screening in QCD: a tricky concept • in leading order QCD (O. Philipsen, hep-ph/0010327) • vv Barbara Jacak QM06
don’t give up! ask lattice QCD Karsch, et al. running coupling coupling drops off for r > 0.3 fm Barbara Jacak QM06
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 QM06
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 QM06
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 QM06
HQ Energy Loss and Flow nucl-ex/0611018 (submitted to Phys. Rev. Lett.) Radiative energy loss only fails to reproduce v2HF. Heavy quark transport model has reasonable agreement with both RAA and v2HF. Small relaxation time t or diffusion coefficient DHQinferred for charm. Talk: F. Kajihara (2.1.07) Barbara Jacak QM06