Workshop “Interaction between Hard Probes and The Bulk”
in 2006 RHIC & AGS annual users’ meeting
Open data table of
hydrodynamic simulations for
jet quenching calculations
Tetsufumi Hirano
Institute of Physics, University of Tokyo
Original work: TH, Yasushi Nara
Collaborators: Masatsugu Isse, Akira Ohnishi, Koji Yoshino
Motivation
• Important Key Topics @ RHIC
– Elliptic flow
– Jet quenching
– Color Glass Condensate
– Particle ratio
– Recombination
–…
• My sole question:
– Are we able to get a consistent picture at
RHIC?
The Five Pillars of RHIC Wisdom
Adapted from T.Hallman
Talk@ICHEP04
Ideal hydro
Early thermalization
+ soft EOS
Statistical model
Quark recombination
 constituent q d.o.f.
…suggest appealing QGP-based
picture of RHIC collision evolution, BUT invoke 5 distinct
models, each with own ambiguities, to get there.
pQCD parton E loss
u, d, s equilibration near
Tcrit
CGC
Very high
anticipated
initial gluon
density
Very high
inferred
initial
gluon
density
Example 1
Particle ratio
PHENIX white paper
Hydro: P.Huovinen
Data: PHENIX
Elliptic flow
Issue: Conventional ideal hydro could not reproduce particle ratio.
Solution: Introduction of chemical freezeout in hydro.
N.Arbex et al.(’01), TH and K.Tsuda(’02), D.Teaney(’02)
Interpretation: Accidental reproduction by ideal hydro.
Necessity of dissipation in the hadron phase.
TH and M.Gyulassy(’06)
Example 2
Color Glass Condensate
Results: Kharzeev and Levin(’01)
Data: PHOBOS
Hydro: P.Huovinen
Data: PHENIX
Elliptic flow
Issue: CGC initial conditions were not implemented in hydro.
Solution: Introduction of CGC initial conditions in hydro.
TH and Y.Nara(’04)
Interpretation: Larger eccentricity from CGC (talk by Y.Nara)
Necessity of dissipation even in the QGP phase!
Hirano,Heinz,Kharzeev,Lacey,Nara, PLB636(’06)299.
Large Eccentricity from CGC Initial
Condition (talk by Y.Nara)
Hirano and Nara(’04), Hirano et al.(’06)
Kuhlman et al.(’06), Drescher et al.(’06)
y
x
Pocket formula (ideal hydro):
v2 ~ 0.2e @ RHIC energies
Ollitrault(’92)
Do we get a consistent picture
also in high pT?
• Bjorken scaling solution,
is often assumed in most jet quenching
calculations.
Life time of partonic phase? (tf<5-10 fm/c)
Transverse flow/profile?
• Sharp edge profile is assumed in some high pT
elliptic flow calculations.
 Contradict to low pT v2.
Violation of Npart2/3 scaling in
RAA(Npart)
Hirano and Nara (’02)
We can interpret the data
if we use Bjorken formula.
(Manifestation of
scaling.)
However, in realistic
situations, partons are
confined into hadrons at
some density.
Thus, a naive
scaling is broken in
peripheral regions.
We make our full 3D hydro results
open to public!
3D hydro+jet
CGC+3D hydro
T.H. and Y.Nara (’02-)
Not the hydro code itself,
but the numerical data table of hydro simulations.
It’s already open!
http://nt1.c.u-tokyo.ac.jp/~hirano
/parevo/parevo.html
http://nt1.c.u-tokyo.ac.jp/~hirano
/parevo/parevo.html
What is Available?
Solution of full 3D hydro simulations:
•Thermalized Parton density r
•Temperature T (>Tc)
•transverse flow (vx,vy)
@ (t, x, y, hs)
Applying Suggestion: Up to you!
Jet quenching
Thermal
radiation
(photon/dilepton)
Recombination
Coalescence
Meson
Baryon
Information
along a path
Information
on surface
Information
inside medium
Functions
Current version:
getrho(tau,x,y,eta): Local parton density
gettemp(tau,x,y,eta): Local temperature
getvx(tau,x,y,eta): Local vx
getvy(tau,x,y,eta): Local vy
getInitialPosition(b,tau0,x,y,eta0):
Initial parton position with binary collision
getInitialPosition(p0,phi0):
Initial parton momentum with power law tail
Next version:
getglv1st(tau,x,y,eta,p0): GLV 1st order
getglv1sts(tau,x,y,eta,p0):
GLV 1st order neglecting kinematics
moliere(p0): Elastic scattering angle
opacityela(p0,opa): Elastic scattering angle at chi
T.Hirano et al.(’06)
Updates in Near Future
Centrality dependence
Rapidity dependence
• Glauber-BGK model
Npart:Ncoll = 85%:15%
• CGC model
Matching I.C. via e(x,y,h)
A Glimpse of Code (1)
Density, temperature, and flow at (t,x,y,h)
A Glimpse of Code (2)
Energy of jet seen from
a co-moving fluid
element:
Calculation of energy loss
T.Hirano, M.Isse, Y.Nara, A.Ohnishi, K.Yoshino, (in preparation).
Application Example:
Hadronization through Jet-Fluid String
Space-time evolution of the QGP fluid
Open data table
Energy loss
 GLV 1st order
String
Fragmentation
PYTHIA
(Lund)
In Rudy Hwa’s language, this model describes
shower-shower, shower-thermal, NOT thermal-thermal.
Comparison btw two mechanisms
Lorentz-boosted thermal parton distribution
at T=Tc hyper surface from hydro simulations
pT distributions
GLV 1st order (simplified) formula
20-30% centrality
Effective parton density from hydro
Independent fragmentation C=2.5-3.0
Jet-fluid string C=8.0
Neglecting many effects
Fitting the pT
data is our
starting point.
•Fluctuation of the number of emitted gluon
•Chemical non-equilibrium in the QGP phase
•Higher order in opacity expansion
•Cronin effect …
v2 @ intermediate-high pT
p
20-30% centrality
v2(JFS) ~ 0.1 at b~8 fm
without assuming
an unrealistic hard sphere
High pT v2 puzzle!?
STAR, PRL93,252301(’04)
Mechanism 1
A fluid parton combines
with a jet parton and forms
a hadronic string in a way
that total momentum is
conserved.
In order to compensate this
effect, one needs additional
parton energy loss in
comparison with independent
fragmentation scheme.
This enhances v2.
Mechanism 2
Direction of jets
~Radial on average
Direction of string
momentum is tilted
to reaction plane
in comparison with
collinear direction.
Direction of flow
~Perpendicular to surface
Summary
• We are now in the next stage to
understand the RHIC data.
(Can we establish a consistent picture?)
• Visit our site!
http://nt1.c.u-tokyo.ac.jp
/~hirano/parevo/parevo.html
• Hadronization through jet-fluid strings as
an application example of the open data
table.
Hydrodynamics in OSCAR
http://www-cunuke.phys.columbia.edu/OSCAR/
•AZHYDRO Ver.0.0
(2+1) D hydro
Author: P.Kolb
•BJ_HYDRO Ver.1.1
(1+1)D hydro
Author:A.Dumitru,
D.H.Rischke
Caveat: “No-Go theorem” for hadron EOS in chemical equilibrium
Only relevant EOS is “rapp250.dat” in AZHYDRO.
TH and M.Gyulassy(’06)