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How should we probe a Strongly Coupled QGP? How should we probe a Strongly Coupled QGP? Edward Shuryak Department of Physics and Astronomy State University.

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Presentation on theme: "How should we probe a Strongly Coupled QGP? How should we probe a Strongly Coupled QGP? Edward Shuryak Department of Physics and Astronomy State University."— Presentation transcript:

1 How should we probe a Strongly Coupled QGP? How should we probe a Strongly Coupled QGP? Edward Shuryak Department of Physics and Astronomy State University of New York Stony Brook NY 11794 USA

2 Not to be discussed in detail Hydro => good description for ..  sQGP seem to be the most perfect fluid known  /s=.1-.2<<1 Relation to other strongly coupled systems, from atomic experiments to string theory To be discussed how strong is strong? => When bound states occure (ES+Zahed,2003) Zero binding lines =>large cross sections => explains small mean free path ? Many colored bound states => solution to several lattice puzzles =>high mutual concistency of lattice data: masses, potentials, EoS

3 Outline cont: new ideas Jet quenching due to ``ionization” of new bound states(I.Zahed+ES) Conical flow from quenched jets (Casalderrey, ES,Teaney) Bound states ( , ,  ) and a near-threshold bump in QGP => dileptons => quasiparticle masses and their interaction (Jorge Casalderrey +ES)

4 Reminder 1: EOS of QCD is such that cs^2 is not a const p/e(e) = EoS along fixed n B /s lines (Hung,ES,hep-ph/9709264).: <= RHIC A gas of Relativistic pions => Relativisitc QGP => The softest point QGP pressure is nearly balanced by the vacuum pressure: p=p(QGP)-B

5 5 Magdeburg hemispheres 1656 We cannot pump the QCD vacuum out, but we can pump in something else, namely the Quark- Gluon Plasma –arguments from 1970’s QGP was looked at as a much simpler thing, to be described by pQCD. We now see it is also quite complicated matter, sQGP…

6 hydro describes both radial and elliptic flows (from Jacak’s talk) protonpion Hydro models: Teaney (w/ & w/o RQMD) Hirano (3d) Kolb Huovinen (w/& w/o QGP) nucl-ex/0410003

7 Why is v2 so sensitive to the initial time? The maximal v2 is at rather peripheral bin => a ``thin almond”.

8 Reminder 2: The beginning of sQGP: a New QCD Phase Diagram, in which ``zero binding lines” first appeared (ES+I.Zahed hep-ph/030726, PRC) it had one colored state, qq already T The lines marked RHIC and SPS show the adiabatic cooling paths Chemical potential  B

9 Why is hydro description so good ? => marginal states with near zero binding provide large cross sections? (ES+Zahed,03, same) Well, can it work ?

10 Elliptic flow with ultracold trapped Li6 atoms, a=> infinity regime via the so called Feshbach resonance The system is extremely dilute, but it still goes into a hydro regime, with an elliptic flow: cross section changes by about 10^6 or so! Is it a good liquid? How good? It works for cold atoms! The coolest thing on Earth, T=10 nK or 10^(-12) eV can actually produce a Micro-Bang !

11 New development: Hydro works for up to 1000 oscillations!  agrees with hydro (red star) at resonance within better than a percent! Viscosity has a strong minimum thereNew development: Hydro works for up to 1000 oscillations!  agrees with hydro (red star) at resonance within better than a percent! Viscosity has a strong minimum there B.Gelman, ES,I.Zahed nucl-th/0410067 Quantum viscosity  hbar n) .3 seem to be reached at t he experimental minimum. About as perfect as sQGP!

12 New hydro phenomenon: a ``conical” flow J.Casalderey-Solana,Edward Shuryak and Derek Teaney,hep-ph/04…..

13 Sonic boom from quenched jets the energy deposited by jets into liquid-like strongly coupled QGP must go into conical shock waves, similar to the well known sonic boom from supersonic planes. We solved relativistic hydrodynamics and got the flow picture If there are start and end points, there are two spheres and a cone tangent to both

14 Distribution of radial velocity v_r (left) and modulus v (right). (note tsunami-like features, a positive and negative parts of the wave)

15 How to observe it? the direction of the flow is normal to Mach cone, defined entirely by ratio of the speed of sound to the speed of light Unlike the (QCD) radiation, the angle is not shrinking 1/  with increase of the momentum of the jet but is the same for all jet momenta At high enough pt a punch through expected, filling the cone

16 Is such a sonic boom already observed? M.Miller, QM04 flow of matter normal to the Mach cone seems to be observed! See data from STAR,  +/- 1.1=2.0,4.2

17 PHENIX jet pair distribution (from B.Jacak) Away-side jets have a ~2  dip at  – 1.1 is a Mach peak around hard parton, for all bins but the most peripheral one Note: it is only projection, shoud be seen better in

18 So, one can determine the speed of sound (=>EoS), but at what time? At kinetic freezeout,  =12-15 fm/c, and that is why we used c s 2 =.16-.2 for resonance gas That was because we considered central collisions (to awoid complications with elliptic flow subtraction) in which a jet has to go about a diameter of Au One can use semi-peripheral and play with Jet orientation relative to collision plane and change timing

19 Back to jets: dE/dx of two types Radiative eloss is large but energy is going into gluons which are still moving relativistically with v=c Radiative eloss is large but energy is going into gluons which are still moving relativistically with v=c Heating and ionization losses: this energy goes into matter. Heating and ionization losses: this energy goes into matter. The second type losses should be equal to hydro drag force calculated for the conical flow The second type losses should be equal to hydro drag force calculated for the conical flow

20 Jet quenching by ``ionization” of new bound states in QGP?

21 Calculation of the ionization rate ES+Zahed, hep-ph/0406100 Smaller than radiative loss if L>.5-1 fm Is there mostly near the zero binding lines, Thus it is different from both radiative and elastic looses, which are simply proportional to density Relates to non-trivial energy dependence of jet quenching (smaller at 62 and near absent at SPS) dE/dx in GeV/fm vs T/T c for a gluon 15,10,5 GeV. Red-elastic, black - ionization

22 Lattice puzzles and ``new spectroscopy”

23 Two lattice puzzles Matsui-Satz: l J/ ,  c dissolves in QGP (thus it was a QGP signal), and yet it is now found (Asakawa-Hatsuda,Karsch et al) that they seem to exist up to T=2T c. or more. Why???? Matsui-Satz: l J/ ,  c dissolves in QGP (thus it was a QGP signal), and yet it is now found (Asakawa-Hatsuda,Karsch et al) that they seem to exist up to T=2T c. or more. Why???? How can pressure be high at T=(1.5-2)T c while q,g quasiparticles are quite heavy? M» 3T, exp(-3)<<1 (it gets parametric in the N=4 SYM as quasiparticles in strong coupling are infinitely heavy m» (g 2 Nc) 1/2 T

24 How strong is strong? For a screened Coulomb potential, Schr.eqn.=>a simple condition for a bound state (4/3)  s (M/M D ebye ) > 1.68 M(charm) is large, M Debye is not, about 2T If  (M d ) indeed runs and is about ½-1, it is large enough to bind charmonium till about T=3T c Since q and g quasiparticles are heavy, M about 3T, they are bound as well !

25 Digression : Relativistic Klein-Gordon eqn has a critical Coulomb coupling for falling onto the center (known since 1920’s) (4/3)  s =1/2 is too strong, a critical value for Klein-Gordon (and it is 1 for Dirac).

26 New ``free energies” for static quarks (from Bielefeld) Upper figure is normalized at small distances: one can see that there is large ``effective mass” for a static quark at T=Tc. Both are not yet the potentials! The lower figure shows the effective coupling constant

27 Fitting F to screened Coulomb Fit from Bielefld group hep-lat/0406036 Note that the Debye radius corresponds to``normal” (still enhanced by factor 2) coupling, while the overall strength of the potential is much larger

28 New potentials should have the entropy term is subtracted, which makes potentials deeper still this is how potential I got look like for T = 1; 1.2; 1.4; 2; 4; 6; 10Tc, from right to left, from ES,Zahed hep-ph/0403127

29 Here is the binding and |psi(0)|^2 is indeed bound till nearly 3 Tc E/2M Vs T/Tc

30 Solving for binary bound states ES+I.Zahed, hep-ph/0403127 In QGP there is no confinement => Hundreds of colored channels may have bound states as well!

31 The pressure puzzle p/p(SB)=.8 from about.3 GeV to very large value. Interpreted as an argument that interaction is relatively weak (0.2) and can be resumed, although pQCD series are bad… BUT: we recently learned that storng coupling result in N=4 SYM leads to about 0.8 as well at g 2 N » 10 This turned out to be the most misleading picture we had, fooling us for nearly 20 years Well known lattice prediction, Karsch et al the pressure as a function of T (normalized to that for free quarks and gluons)

32 The pressure puzzle is resolved! Masses, potentials and EoS from lattice are mutually consistent M/Tc vc T/Tc and p/p SB vs T/Tc

33 ``Polymerization of sQGP? Multibody bound states (Casalderrey and ES, in progress) Qbar - g - g - g -…- g - Q color convoluted inside naturally ``Polymeric chains” are better bound than pairs because instead of m(reduced)=m/2 in relative motion in binaries there is nearly the full mass for polymers

34 Can we verify existence of bound states at T>Tc experimentally? Dileptons from sQGP:

35 A near-threshold enhancement (``bump”) should exist at any T Why bump? Because attraction between anti-q q in QGP enhances annihilation Example: pp(gg) -> t t at Fermilab has a bump near threshold (2m t ) due to gluon exchanges. The nonrelat. Gamow parameter for small velocity z=  (4/3)  s /v > 1, Produces a bump: the Factor z/(1-exp(-z)) Cancels v in phase space

36 dilepton rate: a nonrelativistic approach with realistic potentials (Jorge Casalderrey +ES,hep-ph/0408128)

37 The annihilation rate divided by that for free massless quarks using non-rel. Green function, for lattice-based potential (+ instantons) Im  (M) for T=1.2,1.4,1.7, 3 T c

38 Asakawa-Hatsuda, T=1.4T c Karsch-Laerman, T=1.5 and 3 Tc The widths of these states are being calculated… But one sees these peaks on the lattice!

39 Summary New hydro phenomenon => Conical flow New hydro phenomenon => Conical flow many mesons survive at T>Tc many mesons survive at T>Tc plus hundreds of exotic colored binary states. plus hundreds of exotic colored binary states. Polymers? Polymers? Lattice potentials, masses and EoS are all consistent ! Puzzles resolved Lattice potentials, masses and EoS are all consistent ! Puzzles resolved vectors above Tc can be observed via dileptons: the bound vectors plus a near- threshold bump. vectors above Tc can be observed via dileptons: the bound vectors plus a near- threshold bump. Most likely in the region 1.5 GeV, where 2Mq stays the same in a wide T interval. The width issue is being studiedMost likely in the region 1.5 GeV, where 2Mq stays the same in a wide T interval. The width issue is being studied

40 Now we are ready to move to N=4 SUSY YM at finite T Why this theory is so special? Copling does not run and can be large (or small) at all distances. Copling does not run and can be large (or small) at all distances. AdS/CFT correspondence!!! AdS/CFT correspondence!!!

41 A complete ``gravity dual” for RHIC from 10-d GR? Black Holes + Howking rad. Is used to mimic the finite T Black Holes + Howking rad. Is used to mimic the finite T How black hole is produced can be calculated from GR (tHooft … Nastase) How black hole is produced can be calculated from GR (tHooft … Nastase) Entropy production => black hole formation, falling into it is viscosity Entropy production => black hole formation, falling into it is viscosity Moving brane => hydro expansion Moving brane => hydro expansion (ES,Sin,Zahed, in progress)

42 Classical QED plasma (ze)^2/aT>>1 is a strongly coupled regime: e.g. molted solts (ze)^2/aT>>1 is a strongly coupled regime: e.g. molted solts Molecular dynamics of 1970’s found that diffusion is going down but viscosity reaches a minimum when this param.is about 10 and then grow toward a ``glass” and finally a solid (at param. about 300) Molecular dynamics of 1970’s found that diffusion is going down but viscosity reaches a minimum when this param.is about 10 and then grow toward a ``glass” and finally a solid (at param. about 300)


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