Anisotropic flow from Lee–Yang zeroes: a practical guide

where 〈. . .〉 here denotes an average over many particles and events. In particular, elliptic flow v2 is recognized as a sensitive probe of thermalization at RHIC [2]. While anisotropic flow is by definition a collective effect that involves many particles, it has mostly been analyzed using methods based either on a study of twoparticle correlations [3–5] or on the cumulants of correlations between a few (in practice, up to 8) particles [6]. We recently proposed a new method of analysis [7, 8] that remedies this limitation, and extracts flow from the correlation between a large number of particles instead of only a few. In the following, we introduce the practical recipes for implementing the method, referring the reader to Refs. [7,8] for theoretical justifications.