Energy and system size dependence of charged particle elliptic flow and v2/ɛ scaling

We report measurements of charged particle elliptic flow at mid-rapidity in Au+Au and Cu+Cu collisions at \sqrt{s_{_{NN}}}=62 and 200 GeV. Using correlations between main STAR TPC and forward TPCs ensures minimal bias due to non-flow effects. We further investigate the effect of flow fluctuations on v₂/ɛ scaling studying initial geometry eccentricity fluctuations in the Monte Carlo Glauber model. It is found that accounting for the effect of flow fluctuations improves v₂/ɛ scaling.