Huichao Song The Ohio State University Lawrence Berkeley National Lab Viscous Hydro +URQMD In...
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Transcript of Huichao Song The Ohio State University Lawrence Berkeley National Lab Viscous Hydro +URQMD In...
Huichao Song
The Ohio State University
Lawrence Berkeley National Lab
Viscous Hydro +URQMD
In collaboration with S.Bass, U.Heinz, C.Shen, P.Huovinen & T.Hirano (?)
06/14/2004
May24- July 16, INT Seattle, WA
Quantifying the Properties of Hot QCD Matter
Supported by DOE
Viscous hydrodynamics
0)( xT
S.Bass
Conservation laws:
gpuupeT )()(
u
T
T
2
12 - Israel-Stewart
eqns.
u
T
Tu
2
1)( 0
S
Viscous hydrodynamics
0)( xT
S.Bass
Conservation laws:
gpuupeT )()(
u
T
T
2
12 - Israel-Stewart
eqns.
u
T
Tu
2
1)( 0
S
viscous hydro: near-equilibrium system
pre-equilibrium dynamics + viscous hydro + hadron cascade
Initial conditions viscous hydro + final conditions
Ideal/ViscousHydro + URQMD
2+1 Ideal/Viscous Hydro Hadron Cascade
S.Bass
MC- Particle Generator
Tsw
Convertor: MC particle generator
)],(),([2
)(3
3
3 pxfpxfxdp
pd
dNE eq
i
i
))((
)(
)(2
1),( 2 xpe
x
xT
pppxf
VIS -MC
extracting QGP viscosity from data Luzum & Romatschke, PRC 2008 Glauber CGC
2v
-Effects from highly viscous & non-chemical equilibrium hadronic stage, bulk viscosity …
?16.0/ s NOT so fast !
Effects of viscosity & chemical composition of HRG
(GeV)Tp0 1
~30%
PCE vs.CE (HRG)
Ideal hydro
P. Huovinen 07
- Does hadronic viscosity and partially equilibrium chemistry balance each other in elliptic flow? Is it safe to neglect both of them, when extracting QGP viscosity?
Ideal hydro vs ideal hydro +hadron cascade
~30%
ideal hydro vs. ideal hydro+URQMD (EOSL-PCE)
- EOS L-PCE : Hadronic viscosity (URQMD) leads to ~20% viscous v2 suppression
EOS L-PCE
ideal hydro +URQMD: SM-EOSQ(CE) vs. EOSL-PCE
- EOS L-PCE: Hadronic viscosity (URQMD) leads to ~20% viscous v2 suppression
- SM-EOS Q (CE): effects from hadronic viscosity and PCE (in URQMD) cancel each other in elliptic flow v2 (Ideal hydro+URQMD)
0/ s0/ s
SM-EOS Q (CE)
EOS L-PCE
SM-EOSQ(CE): viscous vs. ideal hydro +URQMD
- SM-EOS Q (CE): effects from hadronic viscosity and PCE (URQMD) cancel each other in elliptic flow v2 (ideal hydro+URQMD)
-This is no longer true in viscous hydro+URQMD -much larger v2 suppression for PT>1GeV: effects from shear viscous correction / EOS
08.0/ s 0/ s
SM-EOS Q (CE)
SM-EOS Q (CE)
ppf ~
EOSL-PCE: ideal vs. viscous hydro + URQMD
-EOS L-PCE: additional v2 suppression by URQMD (ideal/viscous hydro + URQMD behave similarly)
-Larger URQMD viscous v2 suppression in ideal hydro +URQMD
08.0/ s 0/ s
EOS L-PCE EOS L-PCE
Spectra: SM-EOS Q(CE) vs. EOSL-PCE
-EOS L-PCE (correct chemistry below Tch) is preferable
EOS L-PCE
EOS L-PCESM-EOS Q (CE)
SM-EOS Q (CE)
viscous v2 suppression
EOS L-PCE
-EOS L-PCE: v2 suppression increases from ~20% (min visc hydro) to ~30% (min visc hydro + URQMD)
viscous v2 suppression
EOS L-PCE
-EOS L-PCE: v2 suppression increases from ~20% (min visc hydro) to ~30% (min visc hydro + URQMD)
---> significantly reduces the extracted QGP viscosity
ideal/viscous hydro +URQMD: mass splitting
-Radial flow increases the mass splitting between pion and proton; similar behavior in ideal/ viscous hydro +URQMD
EOS L-PCE EOS L-PCE
08.0/ s0/ s
Inte v2: hydro decouple at Tsw vs. hydro+URQMD
-v2 is not fully developed at Tsw; -positive ecc. at Tsw additionally increase of v2 in URQMD
Inte v2: ideal hydro, vis hydro, vis hydro+URQMD
-Additional v2 suppression in URQMD (hadronic stage is highly viscous)
viscous v2 suppression: hydro vs. hydro+URQMD
-larger URQMD viscous v2 suppression for smaller systems
-viscous hydro + URQMD: smaller URQMD viscous v2 suppression, comparing with ideal hydro + URQMD
ideal vs viscous hydro & ideal vs viscous hydro +URQMD
-Viscous v2 suppressions are significantly reduced after a proper treatment of hadronic matter (URQMD)
: ideal Hydro + URQMD
-Hadronic viscosity from URQMD increase the slope of dydNSv /)/1(/2
dydNSv /)/1(/2
: ideal /Viscous Hydro + URQMD (I)
-hadronic viscosity from URQMD increases the slope of dydNSv /)/1(/2
dydNSv /)/1(/2
-hadronic viscosity from URQMD increase the slope of
- v2 is not fully saturated at Tsw the increase of the slope
dydNSv /)/1(/2
: ideal /Viscous Hydro + URQMD (II) dydNSv /)/1(/2
: experimental data Thanks for A. Tang for Exp data
dydNSv /)/1(/2
-Experimental data: v2 , dN/dy ; theoretical estimations: ecc. S (Glauber/CGC) -larger slope and magnitude for v2/ecc. for glauber initial profile
Glauber CGC
A hint for min vis. liquid with CGC initializationThanks for A. Tang for Exp data
- v2/ecc from hydro +URQMD is not sensitive to Glauber /CGC or optical/ fluctuation initializations (need some further calculations)
Glauber CGC
-Theoretical curves are all from Glauber initialization (add cures in the future )
-Overlap area are different for CGC and Glauber initializations
viscous hydro+URQMD
-- a try to extract the hadronic viscosity
vs. viscous hydro with )(/ Ts
EOSL-PCE is an essential input for the calculations here
inte v2 from hydro +URQMD with diff. Tsw
)(/ Ts-with a “perfect” and “correct” chemical components (PCE) for hadrons phase, final results from hydro +URQMD should not be sensitive to Tsw
- is not enough for hadronic viscosity 08.0/ s
inte v2 from hydro +URQMD with diff. Tsw
- is not enough for hadronic viscosity 08.0/ s - over suppresses v2 for T=165-150 MeV, but not enough for T<130 MeV 24.0/ s
inte v2 from hydro +URQMD with diff. Tsw
- is not enough for hadronic viscosity 08.0/ s - over suppresses v2 for T=165-150 MeV, but not enough for T<130 MeV 24.0/ s
extract from URQMD (a first try)
a hint?
24.0~/ s
- is not enough for hadronic viscosity 08.0/ s - over suppresses v2 for T=165-150 MeV, but not enough for T<130 MeV 24.0/ s
)(/ Ts
extract from URQMD (a first try)
?16.0/08.0 s?24.0/16.0 s
?48.0/24.0 s
-please do NOT take the above number too seriously -need further detailed extraction - such extraction gives a special trajectory of URQMD dynamic )(/ Ts
)(/ Ts
A Short Summary
-when extracting the QGP viscosity, one need to consider the effects of hadronic viscosity and the hadronic chemical components
-with viscous hydro+URQMD become available, these two above uncertainties are naturally eliminated
-with a EOS correctly describe PCE HG, it is “somewhat” safe to swtich hydro to URQMD at lower temperature
---> extract the effective URQMD viscosity at some specific dynamical trajectory by comparing hydro with and hydro+URQMD)(/ Ts