Multiparticle azimuthal correlations for extracting event-by-event elliptic and triangular flow in Au plus Au collisions at √SNN=200 GeV

We present measurements of elliptic and triangular azimuthal anisotropy of charged particles detected at forward rapidity 1 < vertical bar eta vertical bar < 3 in Au + Au collisions at root S-NN = 200 GeV, as a function of centrality. The multiparticle cumulant technique is used to obtain the elliptic flow coefficients v(2){2}, v(2){4}, v(2){6}, and v(2){8}, and triangular flow coefficients v(3){2} and v(3){4}. Using the small-variance limit, we estimate the mean and variance of the event-by-event v 2 distribution from v(2){2} and v(2){4}. In a complementary analysis, we also use a folding procedure to study the distributions of v(2) and v(3) directly, extracting both the mean and variance. Implications for initial geometrical fluctuations and their translation into the final-state momentum distributions are discussed.