strongly coupled qgp: new frontiers - stony brook...
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Strongly coupled QGP: New Frontiers
(Quark Matter 2008, Jaipur India)
Edward ShuryakStony Brook
Experimental frontiers(not to be discussed)
High energy: LHCWill ``perfect liquid” be still there?
High luminocity at RHICLow energy/high barion density: RHIC/lowS,NA61 and Fair/GSI => the critical and the “ softest” p oints
Prologue: multiple views on sQGP (which forced us to learn a lot in the last few
years…)
sQGP
Plasma physics
Manybody theory
Lattice simulations
Gauge theories,SUSY modelsBlack hole physics,
String theory
AdS/CFT duality
Monopoles
Quantum mechanics
QuasiparticlesPotentialscorrelators
Bound states of EQP and MQPJ/psi,mesons,baryons,calorons
Stronly coupledcold trappedAtoms: 2nd best liquid
Moleculardynamics
Transport properties,Entropy generation
E/M duality
EoSHydrodynamics
Collective modes Energy loss,Mach cones
Flux tubes->
Bose-EinsteinCondensation->confinement RHIC
data
Fundamental questions (answers?)
• What is the dynamics of confinement/deconfinement?() • What are the magnitude and Tdependence of electric
and magnetic couplings in sQGP? What are the masses and the role of magnetically charged quasiparticles in sQGP? (+)
• Why is quarkgluon plasma (sQGP) at RHIC such a good liquid? (small η/s, TDc ,large dp/dt) (++)
• Is it only true in the RHIC domain T=(12)Tc? Will we see sQGP signals at LHC as well? ()
• AdS/CFT equilibrium results eta/s, jet quenching, conical flow, photon emission. Can one obtain a complete “gravity dual to RHIC” including equilibration/entropy?(+)
• Can we even qualitatively understand AdS/CFT results without duality? ()
outline
• A bit of hydro• Electricmagnetic duality
(fight,competition…)• Gaugestring duality AdS/CFT • Out of equilibium: sGlasma=>sQGP• conclusions
Thermo and hydrodynamics: can they be used at subfm scale?
• Here are three people who asked this question first:• Fermi (1951) proposed strong interaction leading to
equilibration: <n>about s1/4
• Pomeranchuck (1952) introduced freezeout• Landau (1953) explained that one should use hydro in
between, saving Fermi’s prediction via entropy conservation {he also suggested it should work because coupling runs to strong at small distance! No asymptotic freedom yet in 1950’s…}
My own hydro history• Hydro for e+e as a spherical explosion:
PLB 34 (1971) 509 => killed in 1973 by as.freedom and in 1976 by
SLAC discovery of jets in e+e• Looking for it in pp: transverse flow at ISR,
ES+Zhirov, PLB (1979) 253 =>Killed by apparent absence of transverse
flow in pp⇒ ES+Hung, prc57 (1998) 1891, radial flow at
PbPb at CERN SPS worked (but only with correct differential freezeout surfaces!)
• main RHIC finding: Strong radial and elliptic flows are very well described by ideal hydro 20012002: hydro describes radial and elliptic flows for all secondaries , pt<2GeV, centralities, rapidities, A (Cu,Au)… Most theorists/experimentalists were very sceptical but were eventially convinced and the term picked up by D.Teaney and myself in 2003
=> ``the most perfect liquid known” gets official=>AIP declared this to be discovery #1 of 2005 in physics
• Jets destroyed and their energy goes into hydrodynamical ``conical flow” H.Stocker 04, Casalderrey,ES,Teaney 04….
Btw, Mach cone ideas of 1970’s did not work because nucleaiAre not such perfect liquid as sQGP…
So it may be even less than Famous 1/4π!
•Corrections are small for such eta/s Especially at final/later time•v2(pt) is changing at the tail and improvesAgreement at pt>1 GeV •But (my comment) relying on small tails is dangerous
D.Molnar talk here
sQGP is not aGas => BoltsmannApproach inapplicable
Yet it can be used with subdivisionsas a model
As effect of viscosity is small O(10%), thus all other uncertainties have to be included:
initial deformation shown by Raju, but one has to deal with ALL of them
• Color glass produces a bit different initial shape with sharper edge
• Include fluctuations (crucial at large b)
• Time to do UU collisions? ES,nuclth/9906062, BaoAn Li nucl
th/9910030 Heinz, Kuhlman nuclth/041105
4πη/s<1? Generalized viscosity from AdS/CFT (sound)
decreases with k/T, (although we don’t know why)
• M.Lublinsky+ES, hepph0704.1647 PRC ,and in progress
• 4πη/s(k/2πT,ω/2 πT) • Im and Re• Note reduction of Re at
larger k/2πT • Elliptic flow forms early, for
peripheral collisions the almond is thin enough that this effect may play a role: again larger deformed systems needed
Deconfinement and Electricmagnetic
fight/competition in sQGP
.
Magnetic quasiparticles monopoles and dyons are important/dominant at T< 1.5Tc
This affect thermodynamics andespecially transport due tonontrivial “magnetic bottle” effect
Magnetic objects and their dynamics: classics
• ‘t Hooft and Polyakov discovered monopoles in YM gauge theories
• ‘t Hooft and Mandelstamm suggested dual superconductor mechanism for confinement
• Seiberg and Witten shown that it does work in N=2 SYM
electric/magnetic couplings (e/g) must run in the opposite directions! Old good Dirac condition (in QED-type units e2= αs)
at the e=g “ equilibrium line”
αs(el)= αs(mag) =1(the best liquid here?)
Near deconfinement line monopoles much lighter than gluons/quarks
=>αs(mag) small (Landau pole)
=> So αs(el) must be strong!
n=2 (Higgs A0)
Liao,ES hepph/0611131
αs(el)αs(mag)=1αs(el)
αs(mag)
Electric and magnetic scrreningMasses, Nakamura et al, 2004
My arrow shows the ``self-dual” E=M point
Me>MmElectrricdominated
Me<MmMagneticDominated
At T=0 magneticScreening massIs about 2 GeV(de Forcrand et al)(a glueball mass)
(Other lattice data -Karsch et al- show how MeVanishes at Tc better)
ME/T=O(g)ES 78MM/T=O(g^2)Polyakov 79
xCorrelations give MM potential (Mag.length only .1 fm!)
monopole densitystrongly grows as T=> Tc
+
++
Very recent data (thanks to M.D’Elia)confirm that correlation strength
increases with T, indeed opposite to electric
So at least the magnetic coupling does behave as Landau thought
Understanding monopole dynamics
• Claudia Ratti+ES: Higgsing<L(T)> for g,q, tHooftPolyakov monopoles +lattice data (e.g n(mon,T))
=>masses of q,g,m and αs(el,T),αs(mag,T)• Electric Flux Tubes in Magnetic Plasma.Jinfeng
Liao+ES arXiv:0706.4465 derives conditions for (meta) stable flux tubes at T>Tc and explains lattice data on static potentials
• Marco Cristoforetti +ES: Bosecondensation in strongly interacting liquids => Monopole mass at Tc from Feynman condition
BoseEinstein condensation of strongly interacting particles
(with M.Cristoforetti,now TU Munich)
• Feynman theory polygon jumps BEC if ∆S(jump)<Sc=1.651.8
• We calculated ``instantons” for particles jumping paths in a liquid and
solid He4 incuding realistic atomic potentials and confirmed it semiclassically
• Marco is doing Path Integral simulations with permutations numerically, to refine conditions when BEC transitions take place• BEC (confinement) for monopoles• the action calculated relativistically
∆S=M sqrt(d2+(1/Tc)2) = Sc=> M(mon, T= Tc)=O(300 MeV)
<< M(g,q)=O(800 MeV)
Jumping paths:Feynman,interacting
d
and interacting weakly
So why is such plasma a good liquid? Because of magneticbottle trapping:
static eDipole+MPS
+
MV
E+
E
Note that Lorentz force is O(v)!
Monopole rotates around the electric field line, bouncing off both charges (whatever the sign)
We found that two charges play pingpong by a
monopole without even moving!
Dual to Budker’s magnetic bottle
Note that collisions are much more frequent than in cascades
MD simulation for plasma with monopoles (Liao,ES hepph/0611131)
monopole admixture M50=50% etcagain diffusion decreases indefinitely, viscosity does not
D 1/G^(0.6 - 0.8) It matters: 50-50 mixture makes the best liquid, as itcreates ``maximal trapping”
AdS/CFTduality
from gravity in AdS5 to strongly coupled
CFT (N=4 SYM) plasma
(LHC people dream about a black hole formation But it does happen, in each and every RHIC
AuAu event but in the 5th direction! What we see at RHIC is its 4d hologram…)
The first gaugestring duality AdS/CFT, found in 1997!
AdS/CFT correpondence or ``Maldacena AdS/CFT correpondence or ``Maldacena duality” was found on the long path duality” was found on the long path illuminated by Witten, Polyakov, illuminated by Witten, Polyakov, Polchinski, Klebanov… Polchinski, Klebanov… (not so dangerous as Larry McLerran thinks)(not so dangerous as Larry McLerran thinks)
How can it help us?
T=0 setting and the first example of a T=0 setting and the first example of a hologramhologramT nonzero: eta/s, Dc or dp/dt, conical T nonzero: eta/s, Dc or dp/dt, conical flow as the second hologramflow as the second hologramsQLASMA (out of equilibrium): gravity sQLASMA (out of equilibrium): gravity dual for RHIC, dual for RHIC, tdependent hologramtdependent hologram of a falling string, making the entropyof a falling string, making the entropy
The duality setting• CFT (conformal gauge theory) N=4 SYM a cousin of QCD
(chromodynamics=theory of strong interaction) in which the coupling λ=g2Nc does not run.
• It lives on flat 4dim boundary of 5d curved AdS (antideSitter) space where weakly coupled (super)gravity is a description of (super) string theory
• Strategy: calculate in the “bulk”, then project on the boundary
• Hint; think of extra dimension as a complex variable trick: instead of functions on the real axes one may think of poles in a complex plane
The 5th coordinate • the 5th coordinate z, dim=length=1/momentum • its physical meaning is a ``scale” as in renorm.group• z=>0 is ``high scale” UV or very high energies,
z=>infinity is low scale or IR• ds2 =(dt2+dx1
2 +dx22 +dx3
2 +dz2)/z2 so distances in z are logarithmic. Light speed is still 1 in all directions
• z=L2/r where r is distance from b.h. =>Gravity force is acting toward large z, “stones” fall there• (unless they are BPS states which levitate Newton
cancels Coulomb)• AdS/QCD with running coupling g(z): strong in
some region only (Kiritsis et al,07, also my recent proposal of 2 domain scenario ES,07)
Maldacena’s dipole The Coulomb law at strong coupling
• Maldacena,Rey,Yee 98 one of the first apps:
• The string (=flux tube) is pending and has a minimal action
• Modified: at strong coupling, (g2N)1/2 << (g2N) because of shorttime color correlations ES+Zahed,04
• Can it be just a factor, like a dielectric constant?
z
A hologramm of a dipole in a stronly coupled vacuum: not just dielectric
constant and not even only electric E!• Shu Lin,ES arXiv:0707.3135 recently evaluated holographic stress tensor from the Maldacena string Here is large r behavior:
• T00 =>(g2N)1/2d3/r7
Times function of theAngle which is plotted by a solid
line(to be compared to zero coupling=>(g2N)d2/r6
Times another function (dashed)
viscosity from AdS/CFT (Polikastro,Son, Starinets 03)
• T is given by position of a horizon (Witten 98) of nonextreme b.h.• Kubo formula <Tij(x)Tij(y)> => graviton propagator G(x,y) Both viscosity
and entropy are proportional to area of b.h. horizon• Horizon not only has Hawking T and Bekenstein S, but
many other universal properties:T.Damour (1982) => electric conductivity, shear and bulk viscosity
• K.Thorne et al (1980s) put it in the “membrane paradigm” form in which many astrophysical problems were solved
• (e.g. planets rotating around and plunging into B.H., accretion discs with magnetic and electric fields, thermal atmospheres etc)
• => “dissipation is at the bottom” since horizon membrane is black
η /s = hbar /4p
Heavy quark diffusion J.Casalderrey+ D.Teaney,hepph/0605199,hepth/0701123
WORLD
ANTIWORLD
One quark (fisherman) isIn our world,The other (fish) in Antiworld (=conj.amplitude)String connects them and conduct waves in one direction through the black hole
Left: P.Chesler,L.YaffeUp- from Gubser et al
Both groups made Amasingly detailedDescription of the conical flow from AdS/CFT=>very close to hydro but corrections can be inferred
subsonic
supersonic
Photon spectrum has a different shape in sQGP: bremmstrahlung is strongly suppressed while hard photons are
enhanced
sQGP
wQGP
Related to talk by Iancu here
short transport summary log(inverse viscosity s/eta) vs. log(inverse heavy q
diffusion const D*2piT) (avoids messy discussion of couplings)
• RHIC data: very small viscosity and diffusion
• vs theory AdS/CFT and our MD
Weak coupling end =>(Perturbative results shown here)Both related to mean free path
MD results, with specifiedmonopole fraction
->Stronger coupled ->Most perfect liquid
50-50% E/M is the most ideal liquid
4pi
Nonequilibrium “gravity dual” => sGLASMA
• From cold T=0 (extreme BH= mass is minimal for its charge => no horizon AdS ) to hot nonextreme BH with a horizon => T
• extra mass from collision created falling strings: Advantages: naturally dissipative+classical+produce correct Bekenstein entropy S
• Expanding/cooling fireball= departing b.h. horizon in different geometries: 1+d, d=1,2,3 collapses, ( Sin,ES and Zahed 04)
• Bjorken flow: BH longitudinally stratching (JanikPeschanski 05) proposed latetime solution, Sin,Nakamura,Janik viscosity role)
• Spherical nondissipative explosion Big Bang=1+3 departing BH, (Sin,ES and Zahed 04, in ADS Horowitz,Itzhaki,99, Gubser et al, 06)
• nondissipative explosion in 1+1 dim: (Kajantie et al 07)
Gravity dual to the (e+e=>heavy quarks) collision: “Lund model” in AdS/CFT (Shu Lin,ES, I+II papers )
If colliding objects are made of heavy quarks
• Stretching strings are falling under the AdS gravity and don’t break
• Instability of simple scaling solution and numerical studies
• Analogs of longitudinal E,B in wGLASMA
AdS5 center=Extremal b.h.
• a ``holographic image” of this process,• <= timedependent Green function for
linearized Einstein eqns How does it look for a falling string?Is it hydrolike explosion or not?
• Holographic image of a falling string shows an explosion
• (as far as we know the first timedependent hologramm)
• Which however cannot be reprensented as hydro fluid! => anisotropic pressure in the ``comoving frame”
• (like in Raju’s wGLASMA)
T00 , Toi
The story of two membranes:(Many strings falling together)
• Imagine 2 walls of heavy quarks => multiple strings falling (e.g.no dependence on transverse coordinates x2,x3)
• The falling object is thus not a string but 3d membrane (or fabric) to be called Mm (for matter)
• => another (more famous) membrane Mh, (of the “membrane paradigm”) is hovering just above the horizon
The story of two membranes II (textbook example)
• A thin spherical shell of massless “photons” falls radially and horizon is created
• This is in global coordinates: distant observer (we need for AdS/CFT holography) does not see the b.h. interior
Curvatureat membrane jumps =>Israel junctioncondition
The story of two membranes III
(textbook example)
• the stretching and falling “matter membrane” Mm, its ends have +/ v
• horizon membrane Mh bulges upward due to gravity of Mm till they merge
• Fragmentation regions remain nonthermal but in the middle Mm gets substituted by Mh,
• observer at midrapiditysees hydrodynamical
hologram, but not in fragmentation regions
Before equilibration
The horizon membrane can change shape easily provided its area (=entropy)
is preserved as soap film
• Mh is 3dimensional in 5d, if stretched longitudinally a la Hubble x=vt, it moves in z=O(t1/3)=1/r so A=4S= O(x r3)=const (Janik et al)
• In the next to leading order (in powers of inverse time) there is dissipation induced by the Mh viscosity
Questions to think about• Is this “two membrane paradigm” a
AdS/CFT analog to topdown + downup cascades?
(collisional and bremmstrahlung equilibration) • Are instabilities/excitation of falling
strings analogs of plasma instabilities (filamentation)? Unruh T?
• How exactly flling strings get exactly the Bekenstein entropy?
Conclusions• Strongly coupled
QGP produced at RHIC is at T=(12)Tc =>
• This is the region where electric/magnetic couplings cross
• AdS/CFT => natural applications to sQGP. In equilibrium almost done (but not understood)
• RHIC data on transport (eta/s,D),
ADS/CFT and electric/magnetic QGP qualitatively agree!
• Are these two pictures related?
• LHC will tellThis makes so This makes so “perfect liquid” “perfect liquid” because of the because of the magneticmagneticbottle trappingbottle trapping the lowest the lowest
viscosity for viscosity for 50-50% 50-50% electric/magnetic electric/magnetic plasmaplasma
Nonequilibrium timedependentAdS/CFT = sGLASMA•Twomembranes paradigm =>horizon provides T•Equilibration/entropy production in sQGP can benefit from 30 years or work on gravitational collapse+30 years of string theory
Thank you, Indian friends!
Good by,Quark Matter
2008, Jaipur India
reserve
Sonic boom from quenched jets Casalderrey,ES,Teaney, hepph/0410067; H.Stocker…
• the energy deposited by jets into liquidlike strongly coupled QGP must go into conical shock waves
• 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
Wake effect or “sonic boom”
Effective coupling is large! alphas=O(1/21) (not <0.3 as in pQCD applications)
tHooft lambda=g2Nc=4piNc=O(20)>>11
BielefeldBNL lattice group: Karsch et al
Strong coupling in plasma physics: Gamma= <|Epot|>/<Ekin> >>1
gas => liquid => solid• This is of course for
+/ Abelian charges,• But ``green” and
``antigreen” quarks do the same!
• local order would be preserved in a liquid also,
as it is in molten solts (strongly coupled TCP with <pot>/<kin>=O(60), about 3-10 in sQGP)
• RHIC findings: collective flows and jet quenching • Fundamental questions:
Why is quarkgluon plasma (sQGP) at RHIC such a good liquid? Is it related to deconfinement? What is the role of e/m duality and magnetic objects in sQGP? Do AdS/CFT or e/m dualities explain RHIC results?
Viscosity and diffusion constant from AdS/CFT, New meaning of dissipation
Electric and magnetic quasiparticles (EQPs and MQPs) are fighting for dominance (J.F.Liao,ES, hepph/0611131,PRC 07)
The trapping via magnetic bottle effectmolecular dynamics (MD) of NonAbelian plasma with monopoles(B.Gelman, I.Zahed,ES, PRC74,044908,044909 (2006), J.F.Liao,ES, hepph/0611131,PRC 07):
transport summary; both dualities AdS/CFT and sQGP with monopoles seem to work. Summary:Are they related??? LHC will tell
main RHIC finding• Strong radial and elliptic flows are very
well described by ideal hydro => ``the most perfect liquid known”
• Strong jet quenching, well beyond pQCD gluon radiation rate, same for heavy charm quarks (b coming)
• Jets destroyed and their energy goes into hydrodynamical ``conical flow”
20012005: hydro describes radial and elliptic flows for all secondaries , pt<2GeV, centralities, rapidities, A (Cu,Au)…
Experimentalists were very sceptical but wereconvinced and ``nearperfect liquid” is now official,
=>AIP declared this to be discovery #1 of 2005 in physics v_2=<cos(2 phi)>
PHENIX,Nuclex/0410003
red lines are for ES+Lauret+Teaney done before RHIC data, never changed or fitted, describes SPS data as well! It does so because of the correct hadronic matter /freezout via (RQMD)
proton pion(``strong coupling” ideas before RHIC)
PHENIX jet pair distribution Note: it is only
projection of a cone on phi
Note 2: there is also a minimum in
<p_t(\phi)> at180 degr., witha valueConsistent with
background
The most peripheral bin, here there is no QGP
An example of ``dyonic baryon” =finite T instantontop.charge Q=1 config.,
dyons identified via fermionic zero modes
Berlin group - Ilgenfritz et al
Red, blue and green U(1) fields
3 dyons with corresp.Field strengths, SU(3),Each (1,-1,0) charges
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