Transcript Collective Flow Art Poskanzer Exploring the secrets of the universe

Collective Flow
Art Poskanzer
Exploring the secrets
of the universe
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Color by Roberta Weir
Photos
macroscopic nuclear physics
Poskanzer, Swiatecki, 1982
and Seaborg
(1986)
1998
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Spectator-Participant Picture
1973
Abrasion and Ablation of Heavy Ions,
3 J.D. Bowman, W.J. Swiatecki, and C.F. Tsang, LBL-2908 (1973)
Fireball
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G.D. Westfall et al., Phys. Rev. Letters 37, 1202 (1976)
Centrality Dependence
Peripheral Collision
z
y
Y
(near) Central Collision
x
Y
X
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z
y
x
X
Transverse Plane
Transverse Plane
y
x
H. Wieman (2005)
around the beam axis
<y2> - <x2>
ε=
<y2> + <x2>
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Danielewicz
S=πxy
Elliptic Flow
QuickTime™ and a
YUV420 codec decompressor
are needed to see this picture.
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Animation by Jeffery Mitchell (Brookhaven National Laboratory)
Nuclear Collisions
1975
Mass
Bevalac
Energy in cm
Explored to date only on the axes.
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W.J. Swiatecki, Bevalac Upgrade Proposal, 1975.
SPS
RHIC
Kinds of Flow
mainly spectator matter
self quenching
early time
temperature
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Plateau
1984
Temperature
or Pressure
direct photons
elliptic flow
Beam Energy
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W. Swiatecki (1984)
v2 /
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NA49,
C. Alt etand
al.,A.M.
Phys.Poskanzer,
Rev. C 68 Phys.
034903
(2003)
S.A. Voloshin
Letters
B 474, 27 (2000)
Azimuthal Flow Angle
py
px
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S. Voloshin and Y. Zhang, Z. Phys. C 70, 665 (1996)
Fourier Harmonics
Event plane resolution correction made for each harmonic
Unfiltered theory can be compared to experiment!
Voloshin
S. Voloshin and Y. Zhang, hep-ph/940782; Z. Phys. C 70, 665 (1996)
See also, J.-Y. Ollitrault, arXiv nucl-ex/9711003 (1997)
13 and J.-Y. Ollitrault, Nucl. Phys. A590, 561c (1995)
Methods of Analysis
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Pair-wise
Standard
Scalar Product
q-dist
Cumulant
Lee-Yang Zeros
Directed and Elliptic Flow at the SPS
pions
y
pt
15 NA49, C. Alt et al., PRC 68, 034903 (2003)
protons
STAR
QuickTime™ and a
YUV420 codec decompressor
are needed to see this picture.
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First RHIC Elliptic Flow
First paper from STAR
130 GeV/A Au+Au
22 k events
hydro
Data approach hydro
for central collisions
Snellings
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Voloshin
Poskanzer
STAR, K.H. Ackermann et al., PRL 86, 402 (2001)
Elliptic Flow vs. Beam Energy
25% most central
mid-rapidity
all v2
bounce-off
In-plane
elliptic flow
squeeze-out
six decades
18 A. Wetzler (2005)
Directed Flow from Mixed Harmonics
2nd har. event plane
N-particle cumulants
v1{EP1,EP2} 
v1{3}

Removes nonflow
Uses best determined event plane
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STAR, J. Adams et al., PRC submitted (2005)
v1 from Spectator Neutrons
Zero-Degree Calorimeter Shower Max Detector
for transverse deflection of spectator neutrons
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A. Tang, STAR
Quark Coalescence
n = number of
constituent quarks
D. Molnar and S.A. Voloshin, Phys. Rev. Letters 91, 092301 (2003)
21 STAR, Phys. Rev. C 72, 014904 (2005)
Higher Harmonics
vn = 1.2 v2n/2
more details of the event shape in p space
quarks have v4
22 J. Adams et al., PRL 92, 062301 (2004)
Conclusions from Flow
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Hydrodynamics at top RHIC Energy
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Parton Coalescence
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Partonic Phase
Thermalized Partonic Phase
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Thermalization
Quark-Gluon Plasma