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Future experiments inFuture experiments inRelativistic Heavy Ion PhysicsRelativistic Heavy Ion Physics

Rene BellwiedWayne State University

Strangeness in Quark Matter SQM 200724-29 June

Levoca, Slovakia

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To limit the scope a little bit…To limit the scope a little bit… To me SQM is the Quark Matter of Identified Produced

Particle Measurements, preferably with s,c,b content . The scope of this year’s SQM was probably too

expanded. SQM should not be a mini-QM.

I will focus on flavor dependent measurements

I will try to review:– The lessons from RHIC– The low energy running at RHIC and the FAIR programme– RHIC and its future accelerator and detector capabilities

(RHIC-II)– The LHC programme

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Lessons from RHIC: The Quark Soup Lessons from RHIC: The Quark Soup

liquid ?

liquid

plasma

gas

Hirano, Gyulassy (2006)

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From light to heavy, from soft to hardFrom light to heavy, from soft to hard

• participant scaling for light quark hadrons (soft production)• binary scaling for heavy flavor quark hadrons (hard production)• strangeness is not well understood (canonical suppression in pp ?)

PHENIX D-mesons

up, down strange charm

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s-quarks are formed primordials-quarks are formed primordial Scaling according

to quark content?

u, d – scale with Npart

s,c,b – scale with Nbin

p – Npart

K0s – 1/2*Npart + 1/2*Nbin

– 2/3*Npart + 1/3*Nbin

– 1/3*Npart + 2/3*Nbin

– Nbin

– Nbin

D – Nbin

Primordially produced strange quarks have

to recombine with ‘thermal’ u,d quarks

(thermal-shower picture ?)

Normalized to central data

H.Caines, SQM 2004

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The medium consists of constituent quarks ?The medium consists of constituent quarks ?

baryonsbaryons

mesonsmesons

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Nuclear Modification Factor RNuclear Modification Factor Rcpcp

0-5%

40-60%

0-5%

60-80%

√sNN=200 GeV

Baryon and meson suppression sets in at the same quark pT .

√sNN=200 GeV

Strange RCP signals range ofrecombination model relevance

Recombination scaling can be appliedto RCP as well as v2

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Particles are produced differentlyParticles are produced differentlyPartons have different current & constituent quark massPartons have different current & constituent quark mass

up, down strange charm

Productionscaling isdifferent

but v2 is the same !!

and RCP

is thesame !!

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χ2 minimum resultD->e

2σ

4σ

1σ

charm flows like light quarks. An amazing result..charm flows like light quarks. An amazing result.. strong elliptic flow of electrons from

D meson decays → v2D > 0

v2c of charm quarks?

recombination Ansatz: (Lin & Molnar, PRC 68 (2003) 044901)

universal v2(pT) for all quarks simultaneous fit to , K, e v2(pT)

eT

D

cqT

D

uqT

D vpm

mbvp

m

mavpv 2222 )()()(

a = 1

b = 0.96

2/ndf: 22/27

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..which leads to a dramatic conclusion (..which leads to a dramatic conclusion (/s)…./s)…. Simultaneous description of

STAR & PHENIX R(AA) and PHENIX v2 for charm. (Rapp & Van Hees, PRC 71, 2005)

AdS/CFT == /s ~ 1/4 ~ 0.08

pQCD calculation of D (2t)~6(Teaney & Moore, PRC 71, 2005) == /s~1

transport models require– small heavy quark

relaxation time– small diffusion coefficient

DHQ x (2T) ~ 4-6– this value constrains the

ratio viscosity/entropy /s ~ (1.3 – 2) / 4

consistent with light hadron v2 analysis & pT fluctuation analysis (STAR)

…but what does it mean for the partonic degrees of freedom ?

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Interlude: what do we know right now ?Interlude: what do we know right now ? The degree of freedom for light quark particles seems to be a

constituent quark (or a quasi-particle..). It is not massless in the strictest sense, but the ‘mass’ is the same for u,d,s quarks.

Deconfinement, not necessarily chiral symmetry restoration

These degrees of freedom seem to recombine in partonic medium to form hadrons. This is distinctly different from jet fragmentation.

The strange quark seems to be produced primordially, whereas the light quarks a largely ‘thermal’.

Effect should reduce at LHC, if hadronization occurs at same T(canonical suppression melts away (R. Stock))

Interesting test: the charm with a bare quark mass of 1300 MeV. It is definitely produced primordially but it also has a larger ‘thermal’ or ‘interaction’ mass. In other words it is a heavier quasi-particle. How can it show the same flow and the same nuclear suppression ?

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The D-meson issuesThe D-meson issues

FONLL prediction

STAR d+Au (MinBias)

STAR Cu+Cu (MinBias)

STAR Au+Au (MinBias)

PHENIX Au+Au (MinBias)

PHENIX p+p (MinBias + trigger)

pp

M. Floris (NA60), this conference: NA60 & NA50 is also several times above FONLL

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The problem: semi-leptonic decayThe problem: semi-leptonic decay

Kinematicsmearing

B- vs. D-contribution

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Resolving heavy flavor experimental issues Resolving heavy flavor experimental issues with better statistics at LHC energies and with better statistics at LHC energies and

better detectors at RHIC-IIbetter detectors at RHIC-II

Discrepancy between PHENIX and STAR in semi-leptonic D-meson measurements, even in pp

Resolving B- and D-mesons through direct reconstruction of hadronic decay channels

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The solution: The solution: vertex detectors at RHIC and LHCvertex detectors at RHIC and LHC

HFT in STAR (2011 ?)VTX in PHENIX (2010 ?)

IST in ALICE (2008)In addition (ALICE,CMS): B → J/ → or ee

c, b ?

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Lower energies – the search for the critical point.Lower energies – the search for the critical point.

Two dedicated programs: RHIC (2010) – bulk probes FAIR-CBM (2014++) – rare probes

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The Quark Soup – when is it formed ?The Quark Soup – when is it formed ?

liquid ?

liquid

plasma

gas

CP ?

sQGP ?

RHIC

FAIR

1.) is there a 1st order phase transition at FAIR energies ?Is there a critical point ?

2.) is chiral symmetry restored atthe critical point ?

3.) are the degrees of freedom different in the sQGP and at thecritical point ?

4.) is there a QGP at the SPS ?

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Location of the critical pointLocation of the critical point

Ejiri, et.al. 2003Taylor Expansion

Fodor, Katz 2001Lattice Re-weighting

Gavai, Gupta 2005B Lower Limit

B √sNN

———————————————————

180 MeV 25 GeV420 MeV 7.5 GeV725 MeV 4.5 GeV———————————————————

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Achievable Key RHIC Low Energy Achievable Key RHIC Low Energy MeasurementsMeasurements

• • yields and particle ratiosyields and particle ratios T and B

•• identified particle elliptic flow videntified particle elliptic flow v22

collapse of proton flow?

•• K/K/, p/, p/, , ppTT fluctuations fluctuations the critical point signal

• • scale dependence of fluctuationsscale dependence of fluctuations source of the signal

•• vv22 fluctuations fluctuations promising new frontier?

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Major upgrade: 2Major upgrade: 2 TOF for STAR TOF for STARKey detector for measurements of K/ ratio

event-by-event, K/ fluctuations, and enhanced hadronic resonance reconstruction sensitivity at low and high pT

(MRPC)

MultiResistivePlateCounter

Tray Array

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Onset of chiral symmetry restoration at high B

in-medium modifications of hadrons (,, e+e-(μ+μ-), D)

Deconfinement phase transition at high B

excitation function and flow of strangeness (K, , , , ) excitation function and flow of charm (J/ψ, ψ', D0, D, c) sequential melting of J/ψ and ψ', charmonium suppression

The equation-of-state at high B

collective flow of hadrons particle production at threshold energies (open charm)

QCD critical endpoint excitation function of event-by-event fluctuations (K/π,...)

CBM – physics topics and observablesCBM – physics topics and observables

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C. Blume et al., nucl-ex/0409008 Decrease of baryon-chemicalpotential: transition frombaryon-dominatedto meson-dominatedmatter

?

Low energy run at RHIC: remeasurement of K/π (incl. e-by-e)

CBM: Excitation function of multistrange particle production and propagation (collective flow)

Strangeness production at critical point ?Strangeness production at critical point ?

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from Tony Frawley RHIC Users mtg.

at LHC: (10-50) x ~10% of L 25% running time

10 weeks CBMAu+Au 25 AGeV

RHIC-II , LHC, CBM annual yieldsRHIC-II , LHC, CBM annual yields

Nambu model (Fujii et al., hep-ph/0403039)Nambu model (Fujii et al., hep-ph/0403039)CP and the chiral transitionCP and the chiral transition

Massive Scalar

Chiral transition mq=0

Critical point mq>0

Scalar Vector (Baryon-density)

T<Tc

T>Tc

chiral symmetry restoration might decouple from critical point !

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The Quark Soup – when does it vaporize ?The Quark Soup – when does it vaporize ?

liquid ?

liquid

plasma

gas

wQGP ?

sQGP ?

RHIC

LHC ?

1.) is there a wQGP at the LHC ?

2.) is chiral symmetry decoupled from deconfinement in the sQGP ?

3.) are the degrees of freedom different in the sQGP and the wQGP ?

4.) does it matter if the partonicmedium always de-excites through the quark soup phase ?

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Chiral and deconfinement transitions still happen at the same temperature

Interlude: news from Lattice QCDInterlude: news from Lattice QCD(Peter Petreczky, this conference)(Peter Petreczky, this conference)

Critical Temp Tc = 192+- 7 +- 4 MeV(around 40 MeV higher than Tchem)

At high T deviation from ideal gas limit is only about 10%

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SU(3) gauge theory (2+1) flavor QCD

Resummed perturbative calculations from :Blaizot, Iancu, Rebhan, hep-ph/0303185

Lattice data on pressure and entropy density at high temperatures can be described by re-summed perturbation theory

Is 10% a large effect ?Is 10% a large effect ?

Comparison with re-summed perturbation theory, effective 3d theory and additional lattice data on quark number susceptibility and the Debye mass suggest thatwe have wQGP for T > 2 Tc

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AdS/CFT vs. lattice vs. HTLAdS/CFT vs. lattice vs. HTL

J. P. Blaizot, E. Iancu, U. Kraemmer, A. Rebhan, hep-ph/0611393

AdS/CFT

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Proton-proton collisions: Proton-proton collisions: unprecedented physics reach at LHC unprecedented physics reach at LHC

(charged particle spectra)(charged particle spectra)

(from the ALICE physics performance report (J.Phys.G32 (2006)1295))enormous reach in multiplicity and transverse momentum.

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HBT result: HBT result: mmTT dependence of dependence of

radius the same in pp and AA collisions.radius the same in pp and AA collisions.

(Z. Chajecki, (Z. Chajecki, nucl-th/0612080)nucl-th/0612080)

Establish level of collectivity in high multiplicity pp events

elliptic flow component ?elliptic flow component ?(STAR coll., PRC 72 (2005) 014904)(STAR coll., PRC 72 (2005) 014904)

radial flow component ? (blastwave fits)radial flow component ? (blastwave fits)(STAR coll., PRL 92 (2004) 112301)(STAR coll., PRL 92 (2004) 112301)

Program: measure identified spectra, flow & correlations as a function of multiplicityProgram: measure identified spectra, flow & correlations as a function of multiplicity

Hard component increases with NHard component increases with Nchch ? ?

(STAR coll., PRD 74 (2006) 032006)(STAR coll., PRD 74 (2006) 032006) 0ln ( ) /t t ty m p m

n = 1n = 2n = 3

n = 11-12

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Charged particle spectra in Charged particle spectra in quark vs. gluon jetsquark vs. gluon jets(CDF coll., PRL 94 (2005) 171802) (CDF coll., PRL 94 (2005) 171802)

Establish non-Abelian nature of fragmentation process in pp

Identified particle spectra: breakdown of Identified particle spectra: breakdown of mt-scaling due to quark vs gluon jet productionmt-scaling due to quark vs gluon jet production(STAR coll., nucl-ex/0607033)(STAR coll., nucl-ex/0607033)

Excitation function of baryon/meson ratios: fragmentation or recombination ?Excitation function of baryon/meson ratios: fragmentation or recombination ?

Program: measure identified spectra as a function of jet axis, jet energy, jet flavorProgram: measure identified spectra as a function of jet axis, jet energy, jet flavor

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HI Experiments at the LHC ?HI Experiments at the LHC ?All of them are interesting, clearly ALICE is the most versatile and superior HI detector, clearly CMS/ATLAS are superior in calorimeter based jet measurements.

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Heavy Ion collisions: Heavy Ion collisions: unprecedented physics reach at LHCunprecedented physics reach at LHC

from the ALICE EmCal proposalALICE physics performance report (J.Phys.G32 (2006)1295)

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What to expect at the higher energies ?What to expect at the higher energies ?

Is there a significant change in coupling ?Is there a significant change in coupling ? Weaker coupling = larger mean free path = less flow

= less v2 ? Weaker coupling = more viscosity =

more entropy = much larger particle yields ?Detectors go black (‘Pisarski doomsday’ scenario)

The first heavy ion day at the LHC will be very interesting

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spatial eccentricity

momentumanisotropy

Elliptic flow: early creationElliptic flow: early creation P. Kolb, J. Sollfrank and U.Heinz, PRC 62 (2000) 054909

LHC: more viscosity, less flow ?

(RB for R2D group, QM05)

from RHIC to LHC: lifetime of QGP phase nearly doubles

Most hydro calculations suggest

that flow anisotropies are generated

at the earliest stages of the expansion,

on a timescale of ~ 5 fm/c if a

QGP EoS is assumed.

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Hydro pushes to higher pT at the LHCHydro pushes to higher pT at the LHCRuuskanen et al., hep-ph/0510019

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Recombination pushes to higher pTRecombination pushes to higher pTat the LHCat the LHC

Thermal recombination pushes to higher pT because of higher parton <pT>. (Fries, Mueller, EJP C34(2004)S279)

Shower recombination (from overlapping or neighboring jets) pushes recombination out to 20 GeV/c (Hwa, nucl-th/0603053)

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Jet quenching will populate the Jet quenching will populate the recombination region at the LHCrecombination region at the LHC

Borghini and Wiedemann (hep-ph/0506218):solid lines: modified leading logarithm approximation (MLLA)dashed lines: introduce medium effects in parton splitting

=ln(EJet/phadron)

pThadron~2 GeV for

Ejet=100 GeV

Fragmentation strongly modified at pThadron~1-5 GeV even for the highest energy jets

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It will be challenging to interpret the It will be challenging to interpret the intermediate pT region at the LHCintermediate pT region at the LHC

pT

pQCDHydro

~ 2 GeV/c ~ 6 GeV/c

SoftSoft

Medium Medium modifiedmodifiedfragmentation fragmentation (jet quenching)(jet quenching)

0

pT independence of pbar/p ratio.

p/ and /K ratio increases with pT to > 1 at pT ~ 3-4 GeV/c in central collisions.

Suppression factors of p, different to that of , K0

s in the intermediate pT region.

Parton Parton recombinationrecombination

andandcoalescencecoalescence

LHC, RHIC-IISPS, RHIC-I

Thermal

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Identified particle ratios inside andIdentified particle ratios inside andoutside a jetoutside a jet(recombination predicts p/(recombination predicts p/ = 5-20 = 5-20out to 20 GeV/c)out to 20 GeV/c)

Determine the hadronization process & degrees of freedom in medium

Identified particle correlations inside andIdentified particle correlations inside andoutside a jet: outside a jet: Ridge vs. mach cone vs. fragmentationRidge vs. mach cone vs. fragmentation

Program: study identified particle spectra, ratios and correlations asa function of jet energy, jet flavor, fractional momentum, medium path-length

STAR coll., nucl-ex/0703033

STAR coll.,nucl-ex/0701074

PHENIX coll.,PRL 97 (2006) 052301

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Resonance formation insideResonance formation insideand outside a jet & and outside a jet & inside and outside a partonic mediuminside and outside a partonic medium

Search for evidence of chiral symmetry restoration(C. Markert, this conference)

Formation time argument:Formation time argument:a.)a.) General pQCD:General pQCD:Formation time [fm/c] ~ pT [GeV]Formation time [fm/c] ~ pT [GeV]b.) Specific string fragmentation (PYTHIA) b.) Specific string fragmentation (PYTHIA) formalism (Gallmeister, Falter, PLB630, 40 formalism (Gallmeister, Falter, PLB630, 40 (2005)): High pT resonances form early(2005)): High pT resonances form earlyc.) Vitev et al. (hep-ph/0611109): heavy quarks c.) Vitev et al. (hep-ph/0611109): heavy quarks fragment early, i.e. heavy resonances form fragment early, i.e. heavy resonances form early.early.

side 1

side 2

near

away

Program: study resonance formation as a function of jet energy, jet flavor, jet axis, fractional momentum, medium path-length

Low pt High pt

Near side No medium or late hadronic medium

No medium

Away side Late hadronic medium Partonic or early hadronic medium (depends on formation time) CSR ?

Side 1&2 Late hadonic medium Early hadronic medium

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The fate of strangeness enhancement The fate of strangeness enhancement at the LHCat the LHC

Canonical suppression in pp should reduce as a function of the incident energy

The absolute yield rises but only linear with the yield of pions in a QGP

The integrated yield is predictable, the pt-differential yield holds the new physicsHypothesis: due to the higher energy, the remaining differences between u,d and

s quarks should significantly reduce (no Nbin scaling, same d.o.f.)

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I.Kuznetsova & J.Rafelski, (this conference)I.Kuznetsova & J.Rafelski, (this conference)

oversaturated strange phase binds the oversaturated strange phase binds the charm quark ??charm quark ??

cc

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LHC RLHC RccAAAA(p(pTT)/R)/Rbb

AAAA(p(pTT) Prediction) Prediction

– Taking the ratio cancels most normalization differences seen previously

– pQCD ratio asymptotically approaches 1, and more slowly so for increased quenching (until quenching saturates)

– AdS/CFT ratio is flat and many times smaller than pQCD at only moderate pT

W. Horowitz,this conference

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uons from W as a medium-blind referenceuons from W as a medium-blind reference(A.Dainese, this conference)(A.Dainese, this conference) pQCD predicts b/W crossing at pt

muon ~ 30 GeV/c

from W should be unaffected by the medium b-quark energy loss would shift crossing to lower pt

RAA

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LHC Experiments: Muon AcceptanceLHC Experiments: Muon Acceptance

ALICE muon spectrometer: -4 << -2.5 and pt >1 GeV/c

CMS, ATLAS: || < 2.5 and pt > 3.5 GeV/cHigh pt reach in Pb-Pb: about 70-80 GeV/c

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RHIC-II and LHC : unique places to study the RHIC-II and LHC : unique places to study the complete onium programcomplete onium program

– Melting of quarkonium states (Deconfinement TC)Tdiss(’) < Tdiss((3S)) < Tdiss(J/) Tdiss((2S)) < Tdiss((1S))

In order to resolve the question of melting of the states and its relevance to the QGP we need to measure:the J/ production mechanism (octet vs. singlet model) (requires pp)the effect of nuclear absorption (requires pA)the effect of thermal recombination the effect of co-mover absorptionthe feed-down from c (in pp, pA,AA)all states (in pp, pA, AA)

needs to be revised basedon A. Mocsy talk

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J/J/: partonic recombination (PBM): partonic recombination (PBM)

Transport models show similar results based on hadronic recombination (Linnyk & Bravina, this conference)

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Requirement: full coverage and excellent resolution in tracking and calorimetry

and pT broadening for +jet

distribution

for c decay

Y States resolution

R2D

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Summary – Questions for the LHCSummary – Questions for the LHC We have RHIC evidence for constituent quark scaling

above Tc. Is recombination the dominating hadronization process at RHIC and LHC energies ?

Do the hadronizing degrees of freedom in the Quark Gluon Liquid have a dynamic mass ?

Could there be a decoupling of the deconfinement transition and chiral symmetry restoration ?

Is there another transition from the sQGP to the wQGP at LHC energies ?The excitation function (energy dependence) of v2 and R(AA) of identified particles will resolve many of the present ambiguities

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Compelling reasons forCompelling reasons forRHI Physics (RHIC-II, FAIR, LHC) RHI Physics (RHIC-II, FAIR, LHC) B.Jacak (QM06)B.Jacak (QM06) 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?

* could motivatenew experiment

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Ernest O. LawrenceErnest O. Lawrence(Nobel Prize, 1939)(Nobel Prize, 1939)

Father of ‘Big Science’Father of ‘Big Science’

Let’s all work together because there is enough science for everyone !

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Backup slidesBackup slides

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What is missing in HI physics ?What is missing in HI physics ?

Detectors drive the physics output– Hadronic calorimetry– Track by track PID (not dE/dx driven) out to 20

GeV/c– Full tracking, PID and calorimetry out to forward

rapidityMeasurements

– Identified hadron and resonance spectra out to very high pT

-jet, c, Y(1s,2s,3s) measurements– Forward (low x) physics – CGC, fragmentation tests

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A high energy detector for heavy ion physicsA high energy detector for heavy ion physics

R=2.8m

Is it necessary, is it financially achievable ? LHC program will tell us

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STAR preliminary

Do the pT dependenciesin the recombinationresults hint at a more‘massive’ strangequark ?

Light & strange baryon to meson ratiosLight & strange baryon to meson ratios

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Heavy quark energy loss Heavy quark energy loss dependencies (dependencies (ss, gluon density), gluon density)

(S.Wicks, last call for LHC predictions)

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Towards a quantitative resultTowards a quantitative result

M. Stephanov hep-lat/0701002

Large sensitivity to model inputs (such as quark masses), lattice sizes, and other assumptions