Directed flow at RHIC from Lee-Yang zeroes

Borghini N, Ollitrault JY. Directed flow at RHIC from Lee-Yang zeroes. Nuclear Physics A. 2004;742(1-2):130-143.Directed flow in ultrarelativistic nucleus-nucleus collisions is analyzed using the event plane from elliptic flow, which reduces the bias from nonflow effects. We combine this method with the determination of elliptic flow from Lee-Yang zeroes. The resulting method is more consistent and somewhat easier to implement than the previously used method based on three-particle cumulants, and is also less biased by nonflow correlations. Error terms from residual nonflow correlations are carefully estimated, as well as statistical errors. We discuss the application of the method at RHIC and LHC. (C) 2004 Elsevier B.V. All rights reserved