A method for studying initial geometry fluctuations via event plane correlations in heavy ion collisions

Abstract

A method is proposed to measure the relative azimuthal angle distributions involving two or more event planes of different order in heavy ion collisions using a Fourier analysis technique. The analysis procedure is demonstrated for correlations involving two and three event planes (Φn, Φm and Φh). The Fourier coefficients of these distributions are found to coincide with previously proposed correlators, such as cos(6Φ2-6Φ3) and cos(Φ1+2Φ2-3Φ3) etc., hence the method provides a natural framework for studying these correlators at the same time. Using a Monte Carlo Glauber model to simulate Au+Au collisions with fluctuating initial geometry, we are able to identify several new two- or three-plane correlators that have sizable magnitudes and should be measured experimentally. © 2013 The Author(s).