Multi-particle long-range rapidity correlations from fluctuation of the fireball longitudinal shape

Abstract

We calculate the genuine long-range multi-particle rapidity correlation functions, $C_{n}(y_1,...,y_n)$ for $n=3,4,5,6$, originating from fluctuations of the fireball longitudinal shape. In these correlation functions any contribution from the short-range two-particle correlations, and in general up to $(n-1)$-particle in $C_n$, is suppressed. The information about the fluctuating fireball shape in rapidity is encoded in the cumulants of coefficients of the orthogonal polynomial expansion of particle distributions in rapidity.