Quark Matter at RHIC IIhigher luminosity + detector upgrades how does this new plasma work?Barbara JacakStony Brook

Barbara Jacak

RHIC creates fundamentally new matterPressure built up very rapidly during ion collisions at RHIC large collective flow, calculate w/hydroviscosity small, interaction s large, thermalization is fast

huge energy loss by fast quarks traversing mediummedium is opaque large energy & gluon density

baryon production enhanced byfactor of 3 compared to p+p

Barbara Jacak

plasmaionized but macroscopically neutralexhibit collective effectsinteractions among charges of multiple particlesspreads charge out into characteristic (Debye) length, lD>1 particles inside this length, screen each othernormal plasmas: EM interactioncan vary r, T independently photon p, e usually irrelevantcan be strongly or weakly coupledQCD plasmaT determines all properties (heavy q mass sets new scale)intrinsically strongly coupled for accessible Tquarks & gluons NOT asymptotically free to roamnot your mothers plasma

Barbara Jacak

Compelling reasons for higher luminosity*Entirely new questions posed by RHICfast 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 unresolvednature of phase transition? critical point?equation of state of hot QCD matter?do dilepton observables provide evidence for chiral symmetry restoration?

* and upgradingSTAR, PHENIX

Barbara Jacak

RHIC and the phase transitionlattice says: collisions at RHIC map interesting regionRecall per massless degree of freedomTinit ~ 300 MeV

Tfinal ~ 100 MeV

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There is some space left!STARPHENIX

Barbara Jacak

-3 -2 -1 0 1 2 3 rapidity0 f coverage 2pEMCALEMCAL(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 armsUpgraded PHENIX Acceptance

Barbara Jacak

STAR UpgradesDAQ and TPC-FEE upgradeIntegrated Tracking UpgradeHFT pixel detectorBarrel silicon tracker Forward silicon tracker

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STAR TPC performance

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Long term facility strategy

Barbara Jacak

answering the questions with RHIC IIFirst things firstphase transition study and EOSmedium modification of mesons & chiral symmetryexperimentenergy scanprecision measurement of particle flow & dileptonsflow of more massive probesalso probe thermalization, diffusion and viscositytheoryhydro simulations to quantify parameter dep. of flowcan the relationship of dileptons and chiral symmetry be put onto firm theoretical footing?

Barbara Jacak

need to measure T directly!Temperature via blackbody radiationreal & virtual gas 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

Equation of State (also viscosity probe)map p vs. e as a function of collision energy, system sizemeasure c, W, X, f flowsimprove hydro, upgrade PID capabilities p = e /3 for ideal QGPresonance gas p > e /3 generate pressure rather than make more resonances

energy scan to search forcritical point on phase diagram

Barbara Jacak

heavy hadron flow figure of meritpT range of identified hadron v2especially p, L, W

D, B meson flowPHENIX SiVX, RHIC ISTAR, ALICE?

Barbara Jacak

Dileptons & chiral symmetry restoration?Search for critical point bulk hadron production and fluctuationsRequires moderate luminosity do-able in next few years?Chiral symmetry restoration dilepton productionRequires upgraded luminosityWith electron cooling:4 weeks run, 25% recording eff. electron triggers = 20 GeV 109 events 2 GeV 107 eventsCERES ~ 4x107, NA60 sampled ~ 1010 In+In

Increase by factor 100with electron cooling

Barbara Jacak

critical point search

Barbara Jacak

dilepton figure of meritstatistical precision of r,w,f mass measurementspT reach of spectracontinuum between r & f

modify along with previous slide+

Barbara Jacak

Now to the new questionsthermalization mechanism?probe elastic scattering via heavy quark v2 and RAAplasma instability? what is the color screening length? response of plasma to deposited energy?is the initial state a color glass condensate?

Barbara Jacak

role of B decays in electron RAAand v2 ?need RHIC II luminosity & deterctor upgrades direct probe of extent & timescale of thermalization?RHIC II will yield statistics for v2, pT reach for heavy quarksallow scan of systems with exclusive decay channelsrelative abundance of charmed hadron states

inner trackers for PHENIX and STAR

Barbara Jacak

RHIC II luminosity will sort it outfrom Tony Frawley RHIC Users mtg.

Barbara Jacak

screening length: onium spectroscopy

Barbara Jacak

Transport properties transport of particles diffusion

transport of energy by particles thermal conductivity

transport of momentum by particles viscosity

transport of charge by particles electrical conductivityis transport of color charge an analogous question for us?transport in plasmas is driven by collisions

Barbara Jacak

from 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 systemgolden channel: g-jet correlationsg fixes jet energy flavor-tagged jets to sort out g vs. q energy loss

detector upgrades coverage luminosity & DAQ upgrades rate

Barbara Jacak

events per year

Barbara Jacak

challenge: can a jet excite a density wave in the plasma?g radiates energykick particles in the plasmaaccelerate them along the jetnon-equilibrium processneed to update

Barbara Jacak

shear generallya phenomenonin crystals butnot liquids

Barbara Jacak

minimum h at phase boundary?B. Liu and J. Goree, cond-mat/0502009minimum arises because kinetic part of h decreases with G & potential part increases; measure by density-density correlationseen in strongly coupled dusty plasmaCsernai, Kapusta & McLerran nucl-th/0604032

Barbara Jacak

3 particle correlations support cone-like structureJ. Ulery, HP06Need a LOT more statistics to pindown pT ,centrality (&T) dependenceof >2 particle correlations!pT = 3-4 1-2 GeV/c

Barbara Jacak

g-h and g-h-h events per yearstill working on plot

Barbara Jacak

other key measurements at RHIC II

elliptic flow at high pTg elliptic flow g HBT map baryon & multi-strangehadron production poke at the hadronization mechanismprobe 2q correlations in the mediumall have large backgrounds require RHIC II luminosity & detector upgrades to reject background & probe as a function of e, m

Barbara Jacak

RHIC II will get usfrom oh wow!we have found a surprising new form of matter

to aha!here is how it workshow QGP relates to and helps progress in other fields

Barbara Jacak

backup slides

Barbara Jacak

Plasma properties we will measure at RHIC II

propertymeasurementTg, g* as fn. of e, mequation of stateparticle flows as fn. of e, mcritical point locationscreening lengthonium spectroscopyr (x,v)jet tomographydiffusionopen C, B spectra & flowviscositystrange & charmed hadron flows used to constrain 3d hydroenergy transport>2 particle correlations vs. T, pTsomething new?follow up on surprises

Barbara Jacak

to explore at RHIC II 2014

propertymeasurementchallengequantify screening lengthY(2s), Y(3s)

cc in Au+Austatistics (acceptance) resolution? (~100 MeV)S/B, granularity?medium modified fragmentation fn.g-identified hadron correlations>5 GeV/c h statistics (acc)direct g tag/decay subtract. (granularity?? acceptance)chiral symmetrychiral partners (a1, r, p, s) ? doable? granularity?thermalization timeflow of high pT non- p0 di-hadrons pT>20 GeVacceptance, trigger, momentum resolutionplasma parton correlations?something new?

Barbara Jacak

use this technique to measure viscositymelt crystal with laser lightinduce a shear flow (laminar)image the dust to get velocitystudy: spatial profiles vx(y) moments, fluctuations T(x,y) curvature of velocity profile drag forces viscous transport of drag in direction from lasercompare to viscous hydro. extract h/r shear viscosity/mass densityPE vs. KE competition governs coupling & phase of matterCsernai,Kapusta,McLerran nucl-th/0604032

Barbara Jacak

Fast equilibration, high opacity (even for charm): how?multiple collisions using free q,g scattering cross sections doesnt work! need s x50 in the mediumMolnar

Barbara Jacak

Temperature: hydro, eloss say 380-400 MeV Hydro models:Teaney(w/ & w/oRQMD)

Hirano(3d)

Kolb

Huovinen(w/& w/oQGP)

nucl-ex/0410003

Barbara Jacak

strong elliptic flow, scales w/ number of quarks

Barbara Jacak

Plasmas exhibit screeningDebye length: distance where influence of an individual charged particle is felt by the other particles in the plasmacharged particles arrange themselves so as to effectively shield any electrostatic fields within a distance lD

lD = e0kT ------- nee2Debye sphere = sphere with radius lDnumber electrons inside Debye sphere is typically largeND= N/VD= rVD VD= 4/3 p lD3 1/2in strongly coupled plasmas its 1

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Debye screening in QCD: a tricky conceptin leading order QCD (O. Philipsen, hep-ph/0010327)

vv

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dont give up! ask lattice QCDrunning couplingcoupling drops off for r > 0.3 fmKarsch, et al.

Barbara Jacak

screening masses from gluon propagatorScreening mass, mD, defines inverse length scaleInside this distance, an equilibrated plasma is sensitive to insertion of a static sourceOutside its not.

T dependence of electric &magnetic screening massesQuenched lattice studyof gluon propagator

figure shows: mD,m= 3Tc, mD,e= 6Tc at 2Tc lD ~ 0.4 & 0.2 fmmagnetic screening mass is non-zeronot very gauge-dependent, but DOESgrow w/ lattice size (long range is important)Nakamura, Saito & Sakai, hep-lat/0311024

Barbara Jacak

Implications of lD ~ 0.3 fmcan use to estimate Coupling parameter, GG = / but also G = 1/NDfor lD = 0.3fm and e = 15 GeV/fm3VD = 4/3 p lD3 = 0.113 fm3ED = 1.7 GeVto convert to number of particles, use gT or g2Tfor T ~ 2Tc and g2 = 4get ND = 1.2 2.5 G ~ 1NB: for G ~ 1plasma is NOT fully screened its strongly coupled!affects interaction s!other strongly coupled plasmas behave as liquids, even crystals for G 150dusty plasmas, cold atoms+ions , warm dense matter

Barbara Jacak