Constraining QCD transport coefficients in hadron colliders
Akihiko Monnai (KEK, Japan)
with Gabriel Denicol (UFF, Brasil) and Björn Schenke (BNL, USA)
20th InternaLonal Symposium on Very High Energy Cosmic Ray InteracLons May 24, 2018, Nagoya, Japan
G. Denicol, AM, B. Schenke, Phys. Rev. LeY. 116, 212301 (2016)
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn Cosmic ray and nuclear collisions
Transverse momentum spectra
UHECR Nuclear collisions
h
Energy scale:
AIRES by COSMOS, U. Chicago
h
CMS, CERN
√sNN = 300 TeV √sNN = 13 TeV (pp)
UHECR is higher in energy; nuclear colliders allow detailed analyses in a controlled environment
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn High-energy nuclear colliders momentum spectra
RelaLvisLc Heavy Ion Collider (RHIC)@BNL (2000-)
√sNN = 7.7-200 GeV
AA collisions: Cu-Cu, Cu-Au, Au-Au, U-U
pA, dA, hA collisions: √s = 20-200 GeV
pp collisions: √s = 200, 510 GeV
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn High-energy nuclear colliders momentum spectra
RelaLvisLc Heavy Ion Collider (RHIC)@BNL (2000-)
√sNN = 7.7-200 GeV
AA collisions: Cu-Cu, Cu-Au, Au-Au, U-U
pA, dA, hA collisions: √s = 20-200 GeV
Large Hadron Collider (LHC)@CERN (2009-)
AA collisions: Xe-Xe, Pb-Pb
√sNN = 2.76-5.44 TeV
pp collisions: √s = 200, 510 GeV
pA collisions: √s = 5.02, 8.16 TeV
pp collisions: √s = 0.9-13 TeV
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn AA collisions: creaLon of a thermal QCD medium called quark-gluon plasma (QGP) above √sNN ~ 20-200 GeV
Transverse momentum spectra
p/n (in A)
π+ pK+
π-Δ++
γ
γ
Low-momentum hadrons are produced from the medium
γ
γ
K+
π+
p
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn AA collisions: creaLon of a thermal QCD medium called quark-gluon plasma (QGP) above √sNN ~ 20-200 GeV
Transverse momentum spectra
p/n (in A)
π+ pK+
π-Δ++
γ
γ
Low-momentum hadrons are produced from the medium
γ
γ
K+
π+
p
QGP: a high T phase of QCD where quarks are deconfined from hadrons (T > 2×1012 K)
4 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn AA collisions: creaLon of a thermal QCD medium called quark-gluon plasma (QGP) above √sNN ~ 20-200 GeV
Transverse momentum spectra
p/n (in A)
π+ pK+
π-Δ++
γ
γ
Low-momentum hadrons are produced from the medium
γ
γ
K+
π+
p
QGP: a high T phase of QCD where quarks are deconfined from hadrons (T > 2×1012 K)
4 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn How would the QGP affect collider physics?
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn How would the QGP affect collider physics?
SpaLal anisotropy
y
x
5 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn How would the QGP affect collider physics?
SpaLal anisotropy
y
x
In-medium InteracLon
5 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn How would the QGP affect collider physics?
Momentum anisotropySpaLal anisotropy
py
px
y
x
In-medium InteracLon
5 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn How would the QGP affect collider physics?
Momentum anisotropySpaLal anisotropy
py
px
y
x
In-medium InteracLon
Characterized by Fourier harmonics of azimuthal distribuLon
: ellipLc flow
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn Experimental data
Kolb et al., PLB 500, 232 (2001)
Consistent with the nearly-perfect liquid picture up to pT ~ 2 [GeV]
GasGasGas
Liquid: strong-coupling limit
Gas: weak-coupling limit
✓
✗
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn Experimental data
Kolb et al., PLB 500, 232 (2001)
Consistent with the nearly-perfect liquid picture up to pT ~ 2 [GeV]
GasGasGas
Liquid: strong-coupling limit
Gas: weak-coupling limit
✓
- The QGP is strongly-coupled near the quark-hadron transiLon
- We may use hydrodynamics for an effecLve theory of QGP
✗
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn Cosmic ray and nuclear collisions
Transverse momentum spectra
Collider physics has its roots in cosmic ray physics and the study of mulL-parLcle producLon
Fermi, Prog. Theor. Phys. 5, 570 (1950)
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn Cosmic ray and nuclear collisions
Transverse momentum spectra
Collider physics has its roots in cosmic ray physics and the study of mulL-parLcle producLon
Fermi, Prog. Theor. Phys. 5, 570 (1950)
Landau model Landau and Belenkii, Uspekhi Fiz. Nauk 56, 309 (1955)
First introducLon of hydrodynamics to nuclear collisions (*in the context of pp collisions)
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn A modern view of relaLvisLc nuclear collisions
Nuclei (saturated gluons)
Local equilibraLon
Collision
Color glass condensate
Hadronic transport
Freeze-out
Hydrodynamic evoluLon
Glasmaτ < 1 fm
τ = 1-10 fm
τ > 10 fm
τ < 0 fm
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn A modern view of relaLvisLc nuclear collisions
Nuclei (saturated gluons)
Local equilibraLon
Collision
Color glass condensate
Hadronic transport
Freeze-out
Hydrodynamic evoluLon
Glasmaτ < 1 fm
τ = 1-10 fm
τ > 10 fm
τ < 0 fm
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn A modern view of relaLvisLc nuclear collisions
Nuclei (saturated gluons)
Local equilibraLon
Color glass condensate
Hadronic transport
Freeze-out
Hydrodynamic evoluLon
Glasmaτ < 1 fm
τ = 1-10 fm
τ > 10 fm
τ < 0 fm
Collision
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn A modern view of relaLvisLc nuclear collisions
Glasma(Longitudinal color magneLc & electric fields)
Local equilibraLon
Collision
Color glass condensate
Hadronic transport
Freeze-out
Hydrodynamic evoluLon
Glasmaτ < 1 fm
τ = 1-10 fm
τ > 10 fm
τ < 0 fm
8 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn A modern view of relaLvisLc nuclear collisions
Local equilibraLon
Collision
Color glass condensate
Hadronic transport
Freeze-out
Hydrodynamic evoluLon
Glasma
QGP fluid(Aer local thermalizaLon)
τ < 1 fm
τ = 1-10 fm
τ > 10 fm
τ < 0 fm
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn A modern view of relaLvisLc nuclear collisions
Local equilibraLon
Collision
Color glass condensate
Hadronic transport
Freeze-out
Hydrodynamic evoluLon
Glasma
Thermal hadrons
τ < 1 fm
τ = 1-10 fm
τ > 10 fm
τ < 0 fm
9 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn A modern view of relaLvisLc nuclear collisions
Local equilibraLon
Collision
Color glass condensate
Hadronic transport
Freeze-out
Hydrodynamic evoluLon
Glasma
Decay hadronsThermal hadrons
τ < 1 fm
τ = 1-10 fm
τ > 10 fm
τ < 0 fm
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Overview of the modeln Constraining QCD transport coefficients in hadron colliders
IniLal condiLons
RelaLvisLc hydrodynamics
Observables
Hadronic transport
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Overview of the modeln Constraining QCD transport coefficients in hadron colliders
IniLal condiLons
RelaLvisLc hydrodynamics
Observables
EquaLon of state
Transport coefficients
,
InformaLon of QCD
Hadronic transport
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Overview of the modeln Constraining QCD transport coefficients in hadron colliders
IniLal condiLons
RelaLvisLc hydrodynamics
Observables
EquaLon of state
Transport coefficients
,
InformaLon of QCD
Hadronic transport
Experimental dataComparison
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Overview of the modeln Constraining QCD transport coefficients in hadron colliders
IniLal condiLons
RelaLvisLc hydrodynamics
Observables
EquaLon of state
Transport coefficients
,
InformaLon of QCD
Hadronic transport
Experimental dataComparison
Indirect constraining
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Transport coefficientsn Dynamical responses to the gradients of flow ; effecLve
correcLons to the pressure
Shear viscosity = response to deformaLon
Bulk viscosity = response to volume change
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Transport coefficientsn Dynamical responses to the gradients of flow ; effecLve
correcLons to the pressure
relaLvisLc terms relaLvisLc terms
Shear viscosity = response to deformaLon
Bulk viscosity = response to volume change
linear responselinear response
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Transport coefficientsn Dynamical responses to the gradients of flow ; effecLve
correcLons to the pressure
relaLvisLc terms relaLvisLc terms
= DerivaLve of = DerivaLve of
Shear viscosity = response to deformaLon
Bulk viscosity = response to volume change
linear responselinear response
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Transport coefficientsn Dynamical responses to the gradients of flow ; effecLve
correcLons to the pressure
relaLvisLc terms relaLvisLc terms
= DerivaLve of = DerivaLve of
Shear viscosity = response to deformaLon
Bulk viscosity = response to volume change
Bulk viscosity in the conformal limit; shear viscosity dominates
linear responselinear response
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
n No first principle (laÄce QCD) calculaLons so far
Transport coefficients
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
n No first principle (laÄce QCD) calculaLons so far
Transport coefficients
n AnL-de SiYer/conformal field theory (AdS/CFT) duality
“The universal lower bound”
Kovtun, Son, Starinets, PRL 94 (2005) 111601
5-dimesional AdS black hole 4-dimensional
super Yang-Milles theory
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
n No first principle (laÄce QCD) calculaLons so far
Transport coefficients
n AnL-de SiYer/conformal field theory (AdS/CFT) duality
“The universal lower bound”
Kovtun, Son, Starinets, PRL 94 (2005) 111601
5-dimesional AdS black hole 4-dimensional
super Yang-Milles theory
Is it applicable to QCD? – What would be the temperature dependence?
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Observable sensiLve to viscosityn EllipLc flow v2
Kolb et al., PLB 500, 232 (2001)
Shear viscosity can account for deviaLon from local equilibrium at higher pT
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Observable sensiLve to viscosityn EllipLc flow v2
COLD COLDHOT
z
x
Kolb et al., PLB 500, 232 (2001)
Shear viscosity can account for deviaLon from local equilibrium at higher pT
We use rapidity dependence of v2 to extract the temperature dependence of η/s(T)
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Observable sensiLve to viscosityn ParameterizaLon of shear viscosity
0
1
2
3
4
5
0 0.1 0.2 0.3 0.4 0.5
ηT
/(ε+
P)
T[GeV]
(ηT/(ε+P))min=0.04, a=0, b=10 (ηT/(ε+P))min=0.12, a=0, b=0 (ηT/(ε+P))min=0.04, a=10, b=0 (ηT/(ε+P))min=0.04, a=10, b=2
*In the vanishing density limit,
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Observable sensiLve to viscosityn ParameterizaLon of shear viscosity
0
1
2
3
4
5
0 0.1 0.2 0.3 0.4 0.5
ηT
/(ε+
P)
T[GeV]
(ηT/(ε+P))min=0.04, a=0, b=10 (ηT/(ε+P))min=0.12, a=0, b=0 (ηT/(ε+P))min=0.04, a=10, b=0 (ηT/(ε+P))min=0.04, a=10, b=2
*In the vanishing density limit,
The rise in the QGP phase moLvated by perturbaLve QCD;The decrease in the hadronic phase by chiral perturbaLon theory
Csernai, Kapusta and McLerran, PRL 97, 152303 (2006)
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IniLal condiLonsn Phenomenological approach
Glauber model (2D):
Nucleons are distributed according to a Woods-Saxon funcLon
Nucleons in different nuclei are in the distance = Sub-collision
Loizides et al., arXiv: 1408.2549
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IniLal condiLonsn Phenomenological approach
Glauber model (2D):
Nucleons are distributed according to a Woods-Saxon funcLon
Nucleons in different nuclei are in the distance = Sub-collision
Loizides et al., arXiv: 1408.2549
Glauber-Lexus model (3D): AM and Schenke, Phys. LeY. B 752, 317 (2016) Jeon and Kapusta, Phys. Rev. C 56, 468 (1997)
Rapidity is exchanged if there is a sub-collision
Valence quark PDF for the rapidity distribuLon before collisions
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Resultsn EllipLc flow v2, Au-Au collisions at √sNN = 200 GeV
0
1
2
3
4
5
0 0.1 0.2 0.3 0.4 0.5
ηT
/(ε+
P)
T[GeV]
(ηT/(ε+P))min=0.04, a=0, b=10 (ηT/(ε+P))min=0.12, a=0, b=0 (ηT/(ε+P))min=0.04, a=10, b=0 (ηT/(ε+P))min=0.04, a=10, b=2
Large viscosity in the hadronic phase and small viscosity in the QGP phase favored
The minimum is as small as 0.04 (below the lower bound 1/4π)
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Resultsn Triangular flow v3, Au-Au collisions at √sNN = 200 GeV
Large viscosity in the hadronic phase and small viscosity in the QGP phase favored
The minimum is as small as 0.04 (below the lower bound 1/4π)
y
x
ψ3
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Summary and outlookn We have probed collecLve properLes of the hot QCD maYer
RelaLvisLc AA collision can produce the quark-gluon plasma, which behaves as a fluid
QCD shear viscosity is constrained using rapidity dependence of v2 and v3- Large hadronic viscosity and small QGP viscosity
We can explore the QCD transport properLes at finite density for the Beam Energy Scan programs
- The minimum can be smaller than the universal lower bound conjectured in AdS/CFT duality
G. Denicol, C. Gale, S. Jeon, AM, B. Schenke, C. Shen, arXiv:1804.10557 [nucl-th]
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Summary and outlookn We have probed collecLve properLes of the hot QCD maYer
RelaLvisLc AA collision can produce the quark-gluon plasma, which behaves as a fluid
QCD shear viscosity is constrained using rapidity dependence of v2 and v3- Large hadronic viscosity and small QGP viscosity
We can explore the QCD transport properLes at finite density for the Beam Energy Scan programs
- The minimum can be smaller than the universal lower bound conjectured in AdS/CFT duality
G. Denicol, C. Gale, S. Jeon, AM, B. Schenke, C. Shen, arXiv:1804.10557 [nucl-th]
18 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Summary and outlookn We have probed collecLve properLes of the hot QCD maYer
RelaLvisLc AA collision can produce the quark-gluon plasma, which behaves as a fluid
QCD shear viscosity is constrained using rapidity dependence of v2 and v3- Large hadronic viscosity and small QGP viscosity
We can explore the QCD transport properLes at finite density for the Beam Energy Scan programs
- The minimum can be smaller than the universal lower bound conjectured in AdS/CFT duality
G. Denicol, C. Gale, S. Jeon, AM, B. Schenke, C. Shen, arXiv:1804.10557 [nucl-th]
18 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Summary and outlookn We have probed collecLve properLes of the hot QCD maYer
RelaLvisLc AA collision can produce the quark-gluon plasma, which behaves as a fluid
QCD shear viscosity is constrained using rapidity dependence of v2 and v3- Large hadronic viscosity and small QGP viscosity
We can explore the QCD transport properLes at finite density for the Beam Energy Scan programs
- The minimum can be smaller than the universal lower bound conjectured in AdS/CFT duality
G. Denicol, C. Gale, S. Jeon, AM, B. Schenke, C. Shen, arXiv:1804.10557 [nucl-th]
18 / 20
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
OutroducLonn Would there be a QGP in pp and pA collisions?
NO, it is the effect of iniLal state
YES, it is a QGP liquid E.g. Weller and Romatschke, PLB 774,351 (2017)
E.g. Mace, Quark MaYer 2018 talk
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
OutroducLonn Would there be a QGP in pp and pA collisions?
NO, it is the effect of iniLal state
YES, it is a QGP liquid E.g. Weller and Romatschke, PLB 774,351 (2017)
E.g. Mace, Quark MaYer 2018 talk
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
OutroducLonn Would there be a QGP in pp and pA collisions?
NO, it is the effect of iniLal state
YES, it is a QGP liquid E.g. Weller and Romatschke, PLB 774,351 (2017)
E.g. Mace, Quark MaYer 2018 talk
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
The end
Thank you for listening!
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Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn Rapidity distribuLon at Pb-Pb collision in LHC
Transverse momentum spectra
Centrality
central0-5 %
peripheral80-90 %
y = 0 y = 5Rapidity √sNN (eV) systems yp notes
1.3×1013 p-p 9.54 LHC
5.02×1012 Pb-Pb 8.59 LHC
2×1011 Au-Au 5.36 RHIC
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn How would the QGP affects collider physics? (= Evidence of QGP)
Jet quenching
(GeV/c)T
p1 2 3 4 5 6 7
)3 c-2
(mb
GeV
3/d
p3
) or E
d3 c
-2(G
eV3
N/d
p3
Ed
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
4104AuAu Min. Bias x10
2AuAu 0-20% x10
AuAu 20-40% x10
p+p
Turbide et al. PRC69
J/Ψ supression
(radians)! "
-1 0 1 2 3 4
)!
" d
N/d
(T
RIG
GE
R1/N
0
0.1
0.2
d+Au FTPC-Au 0-20%
p+p min. bias
Au+Au Central
)!
" d
N/d
(T
rig
ger
1/N
STAR, PRL 91, 072304 (2003)
Thermal photonsPHENIX, PRL 98, 232301 (2007)
PHENIX, PRL 104, 132301 (2010)
PHENIX, PRL 91, 182301 (2003)
Δφ
×medium absorpLon
In-medium melLng
c
c_
so thermal radiaLon
azimuthal momentum anisotropy
EllipLc flow
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
Observablesn Low-momentum light quarks (u,d,s) are thermalized Transverse
momentum spectra
ObservablesSources
Prompt Thermal Decay
Light-flavor hadrons (π, K, p etc.) ✗ ️
Heavy-flavor hadrons (D, B etc.)
(as quarks) ? ?
High-pT hadrons (jets) ✗ ️✗
Leptons and photons (e±, μ±, γ)
(by medium)
️
Weak bosons (W±, Z0) ✗ ✗
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
IntroducLonn Is the QGP a gas or a liquid?
Transverse momentum spectra
Physicists's predicLon
Liquid: InteracLve parLclesDense
Free parLclesDilute
✓ ✗
Gas:
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
RelaLvisLc hydrodynamicsn Energy-momentum tensor (in the local rest frame)
: energy density
: pressure
: bulk pressure
: shear stress tensor
where
n EquaLon of moLon:
CorrecLons to the pressure
Akihiko Monnai (KEK), ISVHECRI 2018, May 24th 2018
EquaLon of staten Hadron resonance gas + laÄce QCD
LaÄce: Taylor expansion up to the 4th order
HotQCD, PRD 86, 034509 (2012), PRD 90, 094503 (2014), PRD 92, 074043 (2015)
where
Connect to HRG at low T:
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