Measurements of mixed harmonic cumulants in Pb–Pb collisions at sNN=5.02 TeV

Abstract

Correlations between moments of different flow coefficients are measured in Pb-Pb collisions at s NN = 5.02 TeV recorded with the ALICE detector. These new measurements are based on multiparticle mixed harmonic cumulants calculated using charged particles in the pseudorapidity region< 0.8 with the transverse momentum range 0.2 < p T < 5.0 GeV/c. The centrality dependence of correlations between two flow coefficients as well as the correlations between three flow coefficients, both in terms of their second moments, are shown. In addition, a collection of mixed harmonic cumulants involving higher moments of v 2 and v 3 is measured for the first time, where the characteristic signature of negative, positive and negative signs of four-, six-and eight-particle cumulants are observed, respectively. The measurements are compared to the hydrodynamic calculations using iEBE-VISHNU with AMPT and TRENTo initial conditions. It is shown that the measurements carried out using the LHC Run 2 data in 2015 have the precision to explore the details of initial-state fluctuations and probe the nonlinear hydrodynamic response of v 2 and v 3 to their corresponding initial anisotropy coefficients 2 and 3 .