The flow harmonics measurement with the event plane and multi-particle cumulant methods in Pb+Pb collisions at 2.76 TeV in ATLAS

The ATLAS results on charged particles flow harmonics in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV are presented. Elliptic flow and higher order flow harmonics, $v_{n}$ (for n = 2-4), are measured using two methods: standard event plane and multi-particle cumulants (up to 8-th order). Results for elliptic flow are shown in a wide range of pseudorapidity ($|\eta|$ < 2.5), transverse momentum (0.5 < $p_{\mathrm{T}}$ < 20 GeV) and centrality (0-80%). The measurement techniques are discussed in terms of non-flow e ffects. It is shown that four-particle correlations suppress most of non-flow contributions.