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by Art PoskanzerPresented by Hans Georg Ritter

Sergei’s 60th Birthday

16 Nov 13

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Sergei at Work

recent at Wayne State

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Happy Sergei

2008 at Jaipur2002 at MSU

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Sergei Exploring the Unknown

Sergei discovering new physics

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This Talk About Sergeil Highlights that I know

n By yearl Apologies to his co-workersl Mistakes are all mine

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First In-Plane Elliptic Flow

Peaks at 0, pi, and 2pi

AGS E8771994

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First Elliptic Flow, v2

AGS E8771994

v1

v2

v4

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Acceptance Correlationsl Flattening of the Event Plane angle

n Phi Weightingn Recenteringn Shifting

1996

before

after

Flattening the azimuthal distributionof the event plane removes correlationfrom non-uniform acceptance

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Correlation of Q2 with Q1

Black dots, relative to first harmonic,Indicate In-Plane Elliptic Flow

1997

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Negative v1 at Low pT1997

Occurs for heavy particleswith large radial flow

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Methods for analyzing anisotropic flow in relativistic nuclear collisions

50 papers/yearreference the method

Phys. Rev. C 58 1671

A. M. Poskanzer and S. A. Voloshin625 citations from inSPIRE:950 citations from Google

Few author paper.Not a review paper.

1998

Sergei should have beenfirst author, but he insistedthat it be alphabetic.

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Event Plane Resolution

as a function of signal strength and square-root of the multiplicity

for k=1, the plane and particles have the same harmonic

1998

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Scaled v2 vs Transverse Particle Density

1999

Wiggle of v1 vs rapidity

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z

x

Radial flow

<x px> > 0

rapidity

px, v1

x

rapidity

px

x

Baryon stopping

“wiggle”

2000

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STAR Elliptic Flow

2nd harmonic

1st harmonic

2001re

solu

tion

centrality

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Discovery of Elliptic Flow at RHIC

22k events

We worked one whole weekendand came up with this graph

STAR, PRL 86, 402 (2001)

2001

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First RHIC Collective Flow

Raimond Snellings, Sergei Voloshin, and Art Poskanzer

2000

All Happy

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Coalescencel It’s the quarks that flow

n Mesons twice as muchn Baryons three times as much

Mesons and baryons on thesame curve when scaledby the number of quarks

2003

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Use p+p to Estimate Non-Flow2003

All non-flow

Non-flow athigh pT

v2

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Bessel-Gaussianl Gaussian fluctuations give al Bessel-Gaussian distributionl of Qn in Participant Plane

2008

Correlations of more than four particles do not add any information

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Some of Sergei’s Firsts Fourier harmonics 1994 In-plane elliptic flow (at the AGS) 1994 Event plane flattening 1996 Shape of the q-distribution Negative vn at low pT 1997 Event plane resolution correction made

for each harmonic 1998n Unfiltered theory can be compared to

experiment!l Mixed harmonics Use directed and elliptic flow for v1 and v2 RHIC Elliptic Flow 2000

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More of Sergei’s Firstsl v1(y) wiggle 2000l v2{4} from Q-cumulantsl Near-side ridge due to fluctuationsl azHBT proposal Coalescence of constituent quarks 2002

Scaling with number of constituent quarks Use p+p to estimate non-flow 2003l Global polarization proposall Proposed method for strong parity

violation (chiral magnetic effect) Bessel-Gaussian fluctuations 2008

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Still More of Sergei’s Firstsl Event shape engineering 2012l More ...l

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Sergei as a Colleaguel We worked together very welll I would ask a question

n Sergei would thinkn Then answer with great depthn All questions were taken seriously

l Very modestl Wonderful colleaguel Very careful to give credit to others

n But colleagues not listed in this talk

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Bonner Prize

l My only regret:n that Sergei did not share it with me

l In our joint workn All the good ideas have come from Sergei

l He deserves itn Hope he still gets it

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Happy 60th