Measurement of the correlation between flow harmonics of different order in lead-lead collisions at $\sqrt{s_{NN}}$=2.76 TeV with ATLAS

Measurement of the correlation between elliptic or triangular flow coefficients $v_m$ ($m$ = 2, 3) and other flow harmonics $v_n$ ($n$ = 2 to 5) in $\sqrt{s_{NN}}$ = 2.76 TeV Pb+Pb collisions using the data collected by the ATLAS experiment at the LHC is presented. The correlations are measured for the different centrality intervals. Each centrality interval is sub divided into event shape classes defined using the ellipticity or traingularity measured in the forward detectors, and for each of the event shape classes the $v_m - v_n$ correlations are measured in the midrapidity region. $v_2$ and $v_3$ show anticorrelation with each other while nonlinear positive correlations are observed between $v_2-v_4$, $v_2-v_5$ and $v_3-v_5$. The $v_m-v_n$ correlations (for $n$ = 4, 5) are not reproduced by the $\epsilon_m-\epsilon_n$ correlations predicted by initial geometry models, but are found to be well described by a two component model with a linear response contribution and a nonlinear response contribution which is proportional to $v_2^2$, in the case of $v_4$ and to $v_2v_3$, in the case of $v_5$. The linear and nonlinear contributions are extracted from the measured correlations and compared with results from previous event-plane correlation measurements.