Measurements of flow harmonics with the cumulant method from the ATLAS experiment

The measurement of the azimuthal anisotropy of charged particles obtained with the multi-particle correlations method will be presented and compared to the results obtained with the event plane method for Pb+Pb collisions at 2.76 TeV from the ATLAS experiment. Results on flow harmonics, determined from the cumulants of up to eight- particle correlations, will be shown over a wide transverse momentum, 0.5<pT<20 GeV, pseudorapidity (|eta|<2.5) and centrality ranges. The applied cumulant approach provides a unique handle on non-flow effects and allows for the evaluation of the genuine flow fluctuations. Derived estimates of the non-flow correlations and the magnitude of flow fluctuations will be discussed. Centrality and pseudorapidity dependence of the elliptic flow integrated down to very low pT will also be shown and compared to the LHC results as well as to low energy data. A hypothesis of the energy scaling will be examined taking advantage of the large pseudorapidity coverage of the ATLAS experiment.