Akihiko MonnaiDepartment of Physics, The University of Tokyo
Collaborator: Tetsufumi Hirano
Viscous Hydrodynamic Deformation in Rapidity Distributions of the Color Glass Condensate
Workshop for Particle Correlations and Femtoscopy 2011September 24th 2011, The University of Tokyo, Japan
AM and T. Hirano, Phys. Lett. B 703, 583 (2011)
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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Introduction Quark-gluon plasma (QGP) at relativistic heavy ion collisions
Hadron phase QGP phase
(crossover) sQGP (wQGP?)
The QGP quantified as a nearly-perfect fluid
RHIC experiments (2000-)
Viscosity is important in detailed analyses
Introduction
LHC experiments (2010-)
Heavy ion collisions of higher energies
Will the RHIC modeling work at LHC?
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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Introduction Modeling a high-energy heavy ion collision
The First ALICE Result
particles
hadronic phase
QGP phase
Freezeout
Pre-equilibrium
Hydrodynamic stage
Color glass condensate
Hadronic cascade
Initial condition
Hydro to particles
t
z
t
Color glass condensate (CGC)
Relativistic hydrodynamics
Description of saturated gluons in the nuclei before a collision (τ < 0 fm/c)
Description of collective motion of the QGP (τ ~ 1-10 fm/c)
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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The First ALICE Result Mid-rapidity multiplicity
CGC in Heavy Ion Collisions
ALICE data (most central 0-5%)
CGC
Pb+Pb, 2.76 TeV at η = 0K. Aamodt et al. PRL105 252301
MotivationThe CGC is fit to RHIC data; What is happening at LHC?
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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CGC in Heavy Ion Collisions Saturation scale in MC-KLN model
CGC in Heavy Ion Collisions
Fixed via direct comparison with data
dNch/dη gets steeper with increasing λ; RHIC data suggest λ~0.28
Initial conditionfrom the CGC
Hydrodynamic evolution
Observed particle distribution
A missing piece!
Initial conditionfrom the CGC
Observed particle distribution
: thickness function: momentum fraction of incident particles
D. Kharzeev et al., NPA 730, 448H. J. Drescher and Y. Nara, PRC 75, 034905; PRC 76, 041903
dN/dy
λ=0.28λ=0.18
λ=0.38
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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CGC in Heavy Ion Collisions CGC + Hydrodynamic Model
Hydrodynamic Model
Initial conditionfrom the CGC
Hydrodynamic evolution
Observed particle distribution
A missing piece!
The first time the CGC rapidity distribution is discussed in terms of viscous hydrodynamics
We estimate hydrodynamic effects with(i) non-boost invariant expansion(ii) viscous corrections for the CGC
In this work…
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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Hydrodynamic Model Full 2nd order viscous hydrodynamic equations
Model Input for Hydro
Solve in (1+1)-D relativistic coordinates (= no transverse flow) with Landau frame where local energy flux is the flow
EoM for bulk pressure
EoM for shear tensor
Energy-momentum conservation +AM and T. Hirano, NPA 847, 283
All the terms are kept
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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Model Input for Hydro Equation of state and transport coefficients
Boundary conditions at the initial time
Results
Equation of State: Lattice QCD
Shear viscosity: η = s/4π
2nd order coefficients: Kinetic theory
Initial flow: Bjorken flow (i.e. flow rapidity Yf = ηs)
Bulk viscosity: ζeff = (5/2)[(1/3) – cs2]η
Relaxation times: Kinetic theory
S. Borsanyi et al., JHEP 1011, 077
P. Kovtun et al., PRL 94, 111601A. Hosoya et al., AP 154, 229
AM and T. Hirano, NPA 847, 283
Energy distribution: MC-KLN type CGC (averaged over transverse area)
Dissipative currents:
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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Results Distributions at isothermal hypersurface Tf = 0.16 TeV
Results
Outward entropy flux FlatteningEntropy production Enhancement
If the true λ is larger at RHIC, it enhances dN/dy at LHC;Hydro effect is a candidate for explaining the “gap” at LHC
RHIC LHC
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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Results Hydrodynamic parameter dependences (at the LHC)
CGC parameter dependence to be explored
Summary and Outlook
Entropy production is roughly proportional to viscous coefficients Shear viscous effects are dominant in the QGP phase
Fix the real λ from rapidity distribution and centrality dependences
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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Summary and Outlook We solved full 2nd order viscous hydro in (1+1)-dimensions
for the “shattered” color glass condensate
Future prospect includes:– Analyses on the CGC parameter dependences, rcBK, etc…– Estimation of the effects of transverse flow via developing
(3+1)-dimensional viscous hydrodynamic model, etc…
The End
AM & T. Hirano, in preparation
Non-trivial deformation of CGC rapidity distribution due to(i) outward entropy flux (non-boost invariant effect)
(ii) entropy production (viscous effect)
Viscous hydrodynamic effect may play an important role in understanding the seemingly large multiplicity at LHC
WPCF 2011, Sep 24th, The University of Tokyo, Japan
Akihiko Monnai (The University of Tokyo) Viscous Hydrodynamic Deformation in Rapidity Distribution of the Color Glass Condensate
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The End Thank you for listening! Website: http://tkynt2.phys.s.u-tokyo.ac.jp/~monnai/index.html