FLOW STUDY IN RELATIVISTIC NUCLEAR COLLISIONS BY FOURIER EXPANSION OFAZIMUTHAL PARTICLE DISTRIBUTIONS

We propose a new method to study transverse flow effects in relativist ic nuclear collisions by Fourier analysis of the azimuthal distributio n on an event-by-event basis in relatively narrow rapidity windows. Th e distributions of Fourier coefficients provide direct information on the magnitude and type of flow. Directivity and two dimensional spheri city tensor, widely used to analyze how, emerge naturally in our appro ach, since they correspond to the distributions of the first and secon d harmonic coefficients, respectively. The role of finite particle flu ctuations and particle correlations is discussed.