Prescaling and far-from-equilibrium hydrodynamics in the ... · Non-equilibrium QCD descriptions at...
Transcript of Prescaling and far-from-equilibrium hydrodynamics in the ... · Non-equilibrium QCD descriptions at...
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Prescaling and far-from-equilibrium hydrodynamics inthe quark-gluon plasma
Aleksas Mazeliauskas
Institut fur Theoretische PhysikUniversitat Heidelberg
September 23, 2019
AM and Jurgen Berges, Phys. Rev. Lett. 122 (2019) (arXiv:1810.10554)
Isolated quantum systems and universality in extreme conditions
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The Universal Law That Aims Time’s Arrow
Article by Natalie Wolchover, Quanta Magazine (2019)
Thermalization—the end stage of non-equilibrium phenomena.
c©Rolando Barry for Quanta Magazine
How do far-from-equilibrium quantum systems begin to thermalize?2 / 18
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Heavy ion collision experiments at RHIC and LHC
study new phenomena “by distributing high energy or high nucleon densityover a relatively large volume.” – T.D. Lee, 1974
Sorensen, Quark-gluon plasma 4, 2010
Creation of dense QCD matter at extreme temperatures T ∼ 1012 K.3 / 18
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Phase diagram of thermalized QCD matter
neutron star mergers
baryon chemical potential
tem
per
atu
re
heavy ion collisions, early universe
Ding, Karsch, Mukherjee (2015)
Quark-Gluon Plasma—the state with fundamental QCD constituents.4 / 18
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Non-equilibrium QCD descriptions at weak coupling αs → 0
At high energies mid-rapidity is dominated by small Bjorken-x gluons
p ∼ Qs saturation scale � ΛQCD, strong gluon fields Aµ ∼ 1αs� 1
=⇒ classical-statistical simulationsdecoherence of classical fields at τQs � 1
=⇒ kinetic evolution of gluon phase space distribution f
�
J+ J
−
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f ∼ 1αs� 1 1
αs� f � 1 f ∼ 1
Soren Schlichting, Initial Stages 2016Color-Glass Condensate
5 / 18
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Non-equilibrium QCD descriptions at weak coupling αs → 0
At high energies mid-rapidity is dominated by small Bjorken-x gluons
p ∼ Qs saturation scale � ΛQCD, strong gluon fields Aµ ∼ 1αs� 1
=⇒ classical-statistical simulationsdecoherence of classical fields at τQs � 1
=⇒ kinetic evolution of gluon phase space distribution f
�
J+ J
−
E⌘
B⌘
���������������� �����������������������������
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f ∼ 1αs� 1 1
αs� f � 1 f ∼ 1
Soren Schlichting, Initial Stages 2016Color-Glass Condensate
5 / 18
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High temperature gauge kinetic theory
Boltzmann equation for distribution f of quark and gluon quasi-particles.Arnold, Moore, Yaffe (2003)[1]
∂τfg,q −pzτ∂pzfg,q = −C2↔2[f ]− C1↔2[f ]
Leading order processes in the coupling constant λ = 4παsNc:
2↔ 2 elastic scatterings: gg ↔ gg, qq ↔ qq, qg ↔ gq, gg ↔ qq
= |Mggqq |2 = λ2 16
dFCFC2A
[CF
(u
t+t
u
)− CA
(t2 + u2
s2
)]
Hard Thermal Loop resummed propagators, screening mass mD ∼ gTBraaten, Pisarski (1990) [2]
Microscopic studies of QGP equilibration with QCD kinetic theory.Kurkela and Zhu (2015) [3], Keegan, Kurkela, AM and Teaney (2016) [4], Kurkela, AM, Paquet, Schlichting and Teaney
(2018)[5, 6], A. Kurkela, AM (2018) [7, 8], AM, J. Berges (2018)[9]
6 / 18
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High temperature gauge kinetic theory
Boltzmann equation for distribution f of quark and gluon quasi-particles.Arnold, Moore, Yaffe (2003)[1]
∂τfg,q −pzτ∂pzfg,q = −C2↔2[f ]− C1↔2[f ]
Leading order processes in the coupling constant λ = 4παsNc:
1↔ 2 medium induced colinear radiation: g ↔ gg, q ↔ qg, g ↔ qq
= |Mgqq|2 =
k′2 + p′2
k′2p′2p3Fq(k′;−p′, p)︸ ︷︷ ︸
splitting rate
Resummed multiple scatterings with the medium(Landau–Pomeranchuk–Migdal suppression).
Microscopic studies of QGP equilibration with QCD kinetic theory.Kurkela and Zhu (2015) [3], Keegan, Kurkela, AM and Teaney (2016) [4], Kurkela, AM, Paquet, Schlichting and Teaney
(2018)[5, 6], A. Kurkela, AM (2018) [7, 8], AM, J. Berges (2018)[9]
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“Bottom-up” thermalization scenario Baier, Mueller, Schiff, and Son (2001)[11]
Evolution of initially over-occupied hard gluons p ∼ Qs � ΛQCD
I) over-occupied pz ∼ Qs
(Qsτ)1/31� Qsτ � α−3/2s
II) under-occupied pz ∼√αsQs α−3/2s � Qsτ � α−5/2s
III) mini-jet quenching pz ∼ α3sQs(Qsτ) α−5/2s � Qsτ � α−13/5s
pz pz pz
pxpxpx
1 10 100Rescaled occupancy: <pα
sf>/<p>
1
10
100
1000
Anis
otr
opy:
PT/P
L
αs=0
αs=0.03
αs=0.15
αs=0.3
Classical YM
Bottom-Upα
s=0.015
Realisticcoupling
2↔ 2 broadening collinear cascade mini-jet quench
nonthermal attractor
Berges, Boguslavski, Schlichting, Venugopalan (2014) [10]
Kurkela and Zhu (2015), Keegan, Kurkela, AM and Teaney (2016), Kurkela, AM, Paquet, Schlichting and Teaney (2018)
[3, 4, 6, 5]
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“Bottom-up” thermalization scenario Baier, Mueller, Schiff, and Son (2001)[11]
Evolution of initially over-occupied hard gluons p ∼ Qs � ΛQCD
I) over-occupied pz ∼ Qs
(Qsτ)1/31� Qsτ � α−3/2s
II) under-occupied pz ∼√αsQs α−3/2s � Qsτ � α−5/2s
III) mini-jet quenching pz ∼ α3sQs(Qsτ) α−5/2s � Qsτ � α−13/5s
pz pz pz
pxpxpx
1 10 100Rescaled occupancy: <pα
sf>/<p>
1
10
100
1000
Anis
otr
opy:
PT/P
L
αs=0
αs=0.03
αs=0.15
αs=0.3
Classical YM
Bottom-Upα
s=0.015
Realisticcoupling
2↔ 2 broadening collinear cascade mini-jet quench
Berges, Boguslavski, Schlichting, Venugopalan (2014) [10]
Kurkela and Zhu (2015), Keegan, Kurkela, AM and Teaney (2016), Kurkela, AM, Paquet, Schlichting and Teaney (2018)
[3, 4, 6, 5]
7 / 18
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“Bottom-up” thermalization scenario Baier, Mueller, Schiff, and Son (2001)[11]
Evolution of initially over-occupied hard gluons p ∼ Qs � ΛQCD
I) over-occupied pz ∼ Qs
(Qsτ)1/31� Qsτ � α−3/2s
II) under-occupied pz ∼√αsQs α−3/2s � Qsτ � α−5/2s
III) mini-jet quenching pz ∼ α3sQs(Qsτ) α−5/2s � Qsτ � α−13/5s
pz pz pz
pxpxpx
1 10 100Rescaled occupancy: <pα
sf>/<p>
1
10
100
1000
Anis
otr
opy:
PT/P
L
αs=0
αs=0.03
αs=0.15
αs=0.3
Classical YM
Bottom-Upα
s=0.015
Realisticcoupling
2↔ 2 broadening collinear cascade mini-jet quenchhydro attractor
Berges, Boguslavski, Schlichting, Venugopalan (2014) [10]
Kurkela and Zhu (2015), Keegan, Kurkela, AM and Teaney (2016), Kurkela, AM, Paquet, Schlichting and Teaney (2018)
[3, 4, 6, 5]
7 / 18
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From classical simulations to kinetic theory
7
BGLMV (const. anisotropy)
BMSS (elastic scattering)
Turbulence exponents:
α = -2/3
, β = 0 , γ = 1/3 BD (plasma instabilities)
KM (plasma instabilities)
lattice data
1
δS
αS1/7
αS1/3
αS1/2 1 α
S-1
Mom
entu
m s
pace
ani
sotro
py: Λ
L/Λ
T
Occupancy nHard
Hig
her a
niso
tropy
Smaller occupancy
ξ0=1
ξ0=3/2
ξ0=2
ξ0=4
ξ0=6
n0=1n0=1/4
FIG. 5. Evolution in the occupancy–anisotropy plane. In-dicated are the attractor solutions proposed in (BMSS) [1],(BD) [23], (KM) [25] and (BGLMV) [26], along with the sim-ulations results for different initial conditions shown in blue.
While the original work by Baier, Mueller, Schiff andSon [1] (BMSS) determines the basic properties of thekinetic evolution from self-consistency arguments, theself-similar behavior observed from numerical simula-tions indicates that the framework of turbulent ther-malization [36] can be applied. We continue this anal-ysis by plugging the self-similar distribution (10) intoC(elast)[pT , pz; f ] to extract the scaling behavior µ =3α− 2β + γ. The scaling relation in eq. (15), then reads2α−2β+γ+1 = 0. Since elastic scattering processes areparticle number conserving, a further scaling relation isobtained from integrating the distribution function overpT and rapidity wave numbers ν = pzτ . By use of thescaling form (10), particle number conservation leads tothe scaling relation α−2β−γ+1 = 0. Similarly, approxi-mating the mode energy of hard excitations as ωp � pT inthe anisotropic scaling limit, energy conservation yieldsthe final scaling condition α− 3β − γ + 1 = 0.
Remarkably, the above scaling relations are indepen-dent of many of the details of the underlying field the-ory such as the number of colors, the coupling constantas well as the initial conditions. Instead, they only de-pend on the dominant type of kinetic interactions (suchas 2 ↔ 2 or 2 ↔ 3 scattering processes), the con-served quantities of the system and the number of dimen-sions. More specifically, the dynamics of small-angle elas-tic scattering, along with the conservation laws of quasi-particle number and energy provide the three equationsto determine the scaling exponents. These are straight-forwardly extracted to be
α = −2/3 , β = 0 , γ = 1/3 , (18)
in good agreement with those extracted from our latticesimulations of the temporal evolution of gauge invariantobservables.
The close agreement of the lattice simulations with the
bottom-up scenario appears surprising at first. While inthe latter, it is the Debye scale that provides the scalefor multiple incoherent elastic scatterings and the con-sequent broadening of the longitudinal momentum, theone loop self-energy for anisotropic momentum distri-butions could lead to plasma instabilities even at timesτ � Q−1 log2(α−1
S ). The impact of plasma instabilitieson the first stage of the bottom-up scenario has been con-sidered in [23] (BD). In this scenario, plasma instabili-ties create an overpopulation of the unstable soft modesf(p ∼ mD) ∼ 1/αS , such that the interaction of hard ex-citations with the highly populated soft modes becomesthe dominant process. This process leads to a more effi-cient momentum broadening in the longitudinal directionand changes the evolution of the characteristic momen-tum scales and occupancies. Similar considerations, al-beit including a different range of highly occupied unsta-ble modes8, lead to the detailed weak coupling scenarioin [25] (KM). In this scenario, plasma instabilities playa significant role for the entire thermalization process inthe classical regime and beyond. Yet another scenario ofhow highly occupied expanding non-Abelian fields pro-ceed toward thermalization was proposed in [26]. In thisscenario, it is conjectured that the combination of highoccupancy and elastic scattering can generate a transientBose-Einstein condensate. The evolution of this conden-sate together with elastically scattering quasi-particle ex-citations is argued to generate an attractor with fixedPL/PT anisotropy parameter δs.
While all of these effects can in principle be realizedand have interesting consequences for the subsequentspace-time evolution of the strongly correlated plasma,the infrared physics of momenta around the Debye scaleis crucial in all these scenarios. The properties of thishighly non-linear non-Abelian dynamics can be resolvedconclusively through non-perturbative numerical simula-tions, such as those performed here.
A compact summary of our results in comparison withthe different weak coupling thermalization scenarios isshown in Fig. 5, describing the space-time evolution inthe occupancy–anisotropy plane. The horizontal axisshows the occupancy nHard and the vertical axis themomentum-space anisotropy in terms of the typical lon-gitudinal and transverse momenta ΛT,L. The gray linesindicate the attractor solutions of the different thermal-ization scenarios, while the blue lines show our simula-tion results for different initial conditions. One immedi-ately observes the attractor property, which appears tobe in good agreement with the analytical discussion of theBMSS kinetic equation in the high-occupancy regime [5].
As noted previously, similar attractor solutions werediscovered in relativistic scalar theories that purport
8 The range of highly occupied unstable modes in this scenariois determined within the hard-loop framework in Ref. [24] andparametrically given by modes with momenta pT � mD andpz � mDΛT /ΛL.
1 10 100Rescaled occupancy: <pα
sf>/<p>
1
10
100
1000
An
iso
tro
py
: P
T/P
L
αs=0
αs=0.03
αs=0.15
αs=0.3
Classical YM
Bottom-Upα
s=0.015
Realisticcoupling
Berges, Boguslavski, Schlichting, Venugopalan (2014)[12] Kurkela and Zhu (2015)[3]
classical-statistical Yang-Mills kinetic theory of gluons
Occupancy
Anisotropy
scalingscaling
8 / 18
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Non-thermal fixed point (NTFP) for gauge theories
For f ∼ A2 � 1 classical-statistical Yang-Mills describes gluon evolutionAarts, Berges (2002), Mueller, Son (2004), Jeon (2005)
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0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
-0.6 -0.4 -0.2 0 0.2 0.4 0.6
Glu
on
dis
trib
uti
on
: g2 f(
p T=
Q,p
z,τ)
Longitudinal momentum: pz / Q-4 -3 -2 -1 0 1 2 3 4
0
2
4
6
8
10
Res
cale
d d
istr
ibu
tio
n: (
Qτ)
-α g
2 f(p T
=Q
,pz,
τ)
Rescaled momentum: (Qτ)γ pz / Q
Berges, Schenke, Schlichting, Venugopalan (2014) [13] Berges, Boguslavski, Schlichting, Venugopalan (2014) [10]
initial plasma instabilities scaling rescaledlater evolution
Self-similar scaling =⇒ simplification of non-equilibrium physics
fg(p⊥, pz, τ) = ταfS(τβp⊥, τγpz), τ =
√t2 − z2
Universal exponents: α ≈ −23 , β ≈ 0, γ ≈ 1
3scaling in other systems: Orioli et al. (2015) [14], Mikheev et al. (2018) [15], Prufer et al. (2018) [16], Erne et al. (2018) [17]
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Scaling in leading order QCD kinetic theory
Initial conditions fg = σ0g2e−(p
2⊥+ξ
2p2z), σ0 = 0.1, g = 10−3, ξ = 2Scaling regime is reached at late times
fg(p⊥, pz, τ) = τ−2/3fS(p⊥, τ1/3pz), τ → τ/τref
10−3
10−2
10−1
0.01 0.1 1
PL/P
T
τ
free streamingelastic scatterings
QCD kinetic theory
10−3
10−2
10−1
0.1 1
∆τ/τ = 0.28τ
2/3g2f g
(τ,p
⊥,p
z=
0)
p⊥
elastic scatteringsQCD kinetic theory
0.01
0.1
1
τ
pressure anisotropy τ2/3fg(p⊥, pz = 0, τ)
scaling
Approach to a non-thermal fixed point in full QCD kinetic evolution.
10 / 18
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Pre-scaling regime in QCD kinetic theory
Non-equilibrium dynamics undone by self-similar renormalization
fg(p⊥, p⊥, τ) = τα(τ)fS(τβ(τ)p⊥, τγ(τ)pz)
AM and Berges (2018) [9]
Scaling exponents α(τ), β(τ), γ(τ) can be time dependent!
−1.5
−1
−0.5
0
0.5
1
1.5
0.01 0.1 1
1/3
1/4
−2/3
−3/4
σ0 = 0.1
expo
nent
s
τ
α(τ)β(τ)γ(τ)
10−3
10−2
10−1
0.1 1
1/p⊥
∆τ/τ = 0.28
τ−
α(τ
)g2f g
(τ,p
⊥,p
z=
0)
p⊥
QCD kinetic theory
0.01
0.1
1
τ
scaling exponents τ−α(τ)fg(p⊥, pz = 0, τ)
scaling
pre-scaling
Much earlier collapse to scaling solution fS — pre-scaling regime.11 / 18
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Comparison between constant and time dependent exponents
10−3
10−2
10−1
0.1 1
∆τ/τ = 0.28
τ2/3g2f g
(τ,p
⊥,p
z=
0)
p⊥
elastic scatteringsQCD kinetic theory
0.01
0.1
1
τ
10−3
10−2
10−1
0.1 1
1/p⊥
∆τ/τ = 0.28
τ−
α(τ
)g2f g
(τ,p
⊥,p
z=
0)
p⊥
QCD kinetic theory
0.01
0.1
1
τ
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0 0.05 0.1 0.15 0.2
τ2/3g2f g
(τ,p
⊥=
1,p
z)
τ1/3pz
elastic scatteringsQCD kinetic theory
0.01
0.1
1
τ
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0 0.05 0.1 0.15 0.2
τ−
α(τ
)g2f g
(τ,p
⊥=
1,p
z)
τγ(τ)pz
QCD kinetic theory
0.01
0.1
1
τ
scaling pre-scaling
.
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Weighted momentum distribution
f(t, p) = tαfS(tβp)
d3p 1pf(p) d3p f(p) d3p pf(p)
energynumberDebye
p/T
Moments of distribution function probe different momentum scales.13 / 18
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Extracting scaling exponents from integral moments
Pre-scaling evolution
fg(p⊥, pz, τ) = τα(τ)fS(τβ(τ)p⊥, τγ(τ)pz).
imposes relations between integral moments
nm,n(τ) ≡∫ppm⊥ |pz|nfg(p⊥, pz, τ) ∼ τα(τ)−(m+2)β(τ)−(n+1)γ(τ)
Momentum range of scaling solution ⇔ range of moments obeying scaling.
Integrals of Boltzmann equation ⇒ equations of motion for moments
∂τf −pzτ∂pzf = −C[f ]
Relaxation to hydrodynamic solution / relaxation to scaling solution
τππµν + πµν = 2ησµν / τ log τ α+ α = α∞τ
µ(τ)−α(τ)+1.
Time evolution encoded into few hydrodynamic degrees of freedom
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Time dependent exponents
fg(p⊥, p⊥, τ) = τα(τ)fS(τβ(τ)p⊥, τγ(τ)pz)
−1.5
−1
−0.5
0
0.5
1
1.5
0.01 0.1 1
1/3
1/4
−2/3
−3/4
σ0 = 0.1
expo
nent
s
τ
α(τ)β(τ)γ(τ)
Closely related evolution of moments nm,n with 0 ≤ n,m ≤ 315 / 18
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Dependence on initial conditions
Vary initial gluon occupation σ0 = 0.1, 0.6: fg = σ0g2e−(p
2⊥+ξ
2p2z)
−1.5
−1
−0.5
0
0.5
1
1.5
0.01 0.1 1
1/3
1/4
−2/3
−3/4
σ0 = 0.1
expo
nent
s
τ
α(τ)β(τ)γ(τ)
−1.5
−1
−0.5
0
0.5
1
1.5
0.01 0.1 1
1/3
1/4
−2/3
−3/4
σ0 = 0.6
expo
nent
sτ
α(τ)β(τ)γ(τ)
scaling
pre-scaling
scaling
pre-scaling
New hydrodynamic degrees of freedom α(τ), β(τ), γ(τ) far away fromequilibrium.
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The onset of thermalization
Later initialization times =⇒ slower expansionlarger coupling =⇒ stronger interactions
−1.5
−1
−0.5
0
0.5
1
1.5
0.1 1 10
1/3
−2/3
expo
nent
s
τ/τref
α(τ)β(τ)γ(τ)
0.1
0.01 0.1 1
PL/P
T
τT/(4πη/s)
1
10
0.0001 0.001 0.01
anis
otro
pyP
T/P
L
occupancy 〈pλf〉 / 〈p〉
Pre-scaling useful in studying the intermediate regimes of thermalizationscenario.
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Summary and Outlook
fg(p⊥, pz, τ) = τα(τ)fS(τβ(τ)p⊥, τγ(τ)pz)
Scaling and pre-scaling present in full QCD kinetic theory evolution.AM and Berges (2019)
Pre-scaling in classical-statistical Yang-Mills/non-relativistic scalars?see work of Schmied, Mikheev, Gasenzer (2018)[18], poster of Chatrchyan, Geier, Berges
α(τ), β(τ), γ(τ)—new hydrodynamic-like degrees of freedom forevolution not around equilibrium.
Extending pre-scaling description towards the onset of thermalization.Berges, AM, Mikheev, work in progress
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Bibliography I
[1] Peter Brockway Arnold, Guy D. Moore, and Laurence G. Yaffe.Effective kinetic theory for high temperature gauge theories.JHEP, 01:030, 2003, hep-ph/0209353.
[2] Eric Braaten and Robert D. Pisarski.Soft Amplitudes in Hot Gauge Theories: A General Analysis.Nucl. Phys., B337:569–634, 1990.
[3] Aleksi Kurkela and Yan Zhu.Isotropization and hydrodynamization in weakly coupled heavy-ion collisions.Phys. Rev. Lett., 115(18):182301, 2015, 1506.06647.
[4] Liam Keegan, Aleksi Kurkela, Aleksas Mazeliauskas, and Derek Teaney.Initial conditions for hydrodynamics from weakly coupled pre-equilibrium evolution.JHEP, 08:171, 2016, 1605.04287.
[5] Aleksi Kurkela, Aleksas Mazeliauskas, Jean-Francois Paquet, Soren Schlichting, and DerekTeaney.Effective kinetic description of event-by-event pre-equilibrium dynamics in high-energyheavy-ion collisions.Phys. Rev., C99(3):034910, 2019, 1805.00961.
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Bibliography II
[6] Aleksi Kurkela, Aleksas Mazeliauskas, Jean-Francois Paquet, Soren Schlichting, and DerekTeaney.Matching the Nonequilibrium Initial Stage of Heavy Ion Collisions to Hydrodynamics withQCD Kinetic Theory.Phys. Rev. Lett., 122(12):122302, 2019, 1805.01604.
[7] Aleksi Kurkela and Aleksas Mazeliauskas.Chemical equilibration in hadronic collisions.Phys. Rev. Lett., 122:142301, 2019, 1811.03040.
[8] Aleksi Kurkela and Aleksas Mazeliauskas.Chemical equilibration in weakly coupled QCD.Phys. Rev., D99(5):054018, 2019, 1811.03068.
[9] Aleksas Mazeliauskas and Jurgen Berges.Prescaling and far-from-equilibrium hydrodynamics in the quark-gluon plasma.Phys. Rev. Lett., 122(12):122301, 2019, 1810.10554.
[10] J. Berges, K. Boguslavski, S. Schlichting, and R. Venugopalan.Turbulent thermalization process in heavy-ion collisions at ultrarelativistic energies.Phys. Rev., D89(7):074011, 2014, 1303.5650.
[11] R. Baier, Alfred H. Mueller, D. Schiff, and D. T. Son.’Bottom up’ thermalization in heavy ion collisions.Phys. Lett., B502:51–58, 2001, hep-ph/0009237.
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Bibliography III
[12] Juergen Berges, Kirill Boguslavski, Soeren Schlichting, and Raju Venugopalan.Universal attractor in a highly occupied non-Abelian plasma.Phys. Rev., D89(11):114007, 2014, 1311.3005.
[13] Jurgen Berges, Bjorn Schenke, Soren Schlichting, and Raju Venugopalan.Turbulent thermalization process in high-energy heavy-ion collisions.Nucl. Phys., A931:348–353, 2014, 1409.1638.
[14] A. Pineiro Orioli, K. Boguslavski, and J. Berges.Universal self-similar dynamics of relativistic and nonrelativistic field theories nearnonthermal fixed points.Phys. Rev., D92(2):025041, 2015, 1503.02498.
[15] Aleksandr N. Mikheev, Christian-Marcel Schmied, and Thomas Gasenzer.Low-energy effective theory of non-thermal fixed points in a multicomponent Bose gas.2018, 1807.10228.
[16] Maximilian Prufer, Philipp Kunkel, Helmut Strobel, Stefan Lannig, Daniel Linnemann,Christian-Marcel Schmied, Jurgen Berges, Thomas Gasenzer, and Markus K. Oberthaler.Observation of universal dynamics in a spinor Bose gas far from equilibrium.Nature, 563(7730):217–220, 2018, 1805.11881.
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Bibliography IV
[17] Sebastian Erne, Robert Bucker, Thomas Gasenzer, Jurgen Berges, and JorgSchmiedmayer.Universal dynamics in an isolated one-dimensional Bose gas far from equilibrium.Nature, 563(7730):225–229, 2018, 1805.12310.
[18] Christian-Marcel Schmied, Aleksandr N. Mikheev, and Thomas Gasenzer.Prescaling in a far-from-equilibrium Bose gas.Phys. Rev. Lett., 122(17):170404, 2019, 1807.07514.
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