Sergei’s 60 th Birthday

Sergei’s 60th Birthday by Art Poskanzer Presented by Hans Georg Ritter 16 Nov 13

Sergei at Work recent at Wayne State

Happy Sergei 2002 at MSU 2008 at Jaipur

Sergei Exploring the Unknown Sergei discovering new physics

This Talk About Sergei • Highlights that I know • By year • Apologies to his co-workers • Mistakes are all mine

First In-Plane Elliptic Flow 1994 AGS E877 Peaks at 0, pi, and 2pi

First Elliptic Flow, v2 1994 AGS E877 v1 v2 v4

Acceptance Correlations 1996 • Flattening of the Event Plane angle • Phi Weighting • Recentering • Shifting before Flattening the azimuthal distribution of the event plane removes correlation from non-uniform acceptance after

Correlation of Q2 with Q1 Black dots, relative to first harmonic, Indicate In-Plane Elliptic Flow 1997

Negative v1 at Low pT 1997 Occurs for heavy particles with large radial flow

Methods for analyzing anisotropic flow in relativistic nuclear collisions 1998 A. M. Poskanzer and S. A. Voloshin 950 citations from Google 625 citations from inSPIRE: 50 papers/year reference the method Few author paper. Not a review paper. Sergei should have been first author, but he insisted that it be alphabetic. Phys. Rev. C 581671

Event Plane Resolution 1998 as a function of signal strength and square-root of the multiplicity for k=1, the plane and particles have the same harmonic

Scaled v2vsTransverse Particle Density 1999

x x z rapidity x px, v1 px rapidity Wiggle of v1vs rapidity 2000 Baryon stopping Radial flow <x px> >0 “wiggle”

STAR Elliptic Flow 2001 2nd harmonic resolution 1st harmonic centrality

Discovery of Elliptic Flow at RHIC 2001 22k events We worked one whole weekend and came up with this graph STAR, PRL 86, 402 (2001)

First RHIC Collective Flow 2000 Raimond Snellings, Sergei Voloshin, and Art Poskanzer All Happy

Coalescence 2003 • It’s the quarks that flow • Mesons twice as much • Baryons three times as much Mesons and baryons on the same curve when scaled by the number of quarks

Use p+p to Estimate Non-Flow 2003 v2 Non-flow at high pT All non-flow

Bessel-Gaussian 2008 • Gaussian fluctuations give a • Bessel-Gaussian distribution • of Qnin Participant Plane Correlations of more than four particles do not add any information

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 1998 • Unfiltered theory can be compared to experiment! • Mixed harmonics • Use directed and elliptic flow for v1 and v2 • RHIC Elliptic Flow 2000

More of Sergei’s Firsts • v1(y) wiggle 2000 • v2{4} from Q-cumulants • Near-side ridge due to fluctuations • azHBT proposal • Coalescence of constituent quarks 2002 Scaling with number of constituent quarks • Use p+p to estimate non-flow 2003 • Global polarization proposal • Proposed method for strong parity violation (chiral magnetic effect) • Bessel-Gaussian fluctuations 2008

Still More of Sergei’s Firsts • Event shape engineering 2012 • More ...

Sergei as a Colleague • We worked together very well • I would ask a question • Sergei would think • Then answer with great depth • All questions were taken seriously • Very modest • Wonderful colleague • Very careful to give credit to others • But colleagues not listed in this talk

Bonner Prize • My only regret: • that Sergei did not share it with me • In our joint work • All the good ideas have come from Sergei • He deserves it • Hope he still gets it

Happy 60th

Sergei’s 60 th Birthday