Elliptic flow fluctuations in Au+Au collisions at

Abstract

We report first measurements of elliptic flow (v2) fluctuations for the STAR collaboration at middle rapidity in collisions. We analyse the multiplicity dependence of the flow vector length distribution to disentangle non-flow correlations from v2 fluctuations. We find that the width of the v2 distribution is approximately 36% of the mean v2 and, within errors, independent of collision centrality. This value coincides with eccentricity fluctuations, apparently leaving little room for other sources of fluctuations.