Measurements of mixed harmonic cumulants in Pb-Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}=5.02$ TeV

Abstract

Correlations between moments of different flow coefficients are measured in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV recorded with the ALICE detector. These new measurements are based on multiparticle mixed harmonic cumulants calculated using charged particles in the pseudorapidity region $|\eta |<0.8$ with the transverse momentum range $0.2<p_{\mathrm{T}}<5.0$ 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 ${\epsilon }_2$ and ${\epsilon }_3$. These new studies on correlations between three flow coefficients as well as correlations between higher moments of two different flow coefficients will pave the way to tighten constraints on initial-state models and help to extract precise information on the dynamic evolution of the hot and dense matter created in heavy-ion collisions at the LHC.

23 pages, 7 captioned figures, authors from page 18, published version, figures at http://alice-publications.web.cern.ch/node/6815

References in corpus (12)

• An Introduction to PYTHIA 8.2
• Breaking of factorization of two-particle correlations in hydrodynamics
• $v_4$, $v_5$, $v_6$, $v_7$: nonlinear hydrodynamic response versus LHC data
• Characterizing flow fluctuations with moments
• Event-shape fluctuations and flow correlations in ultra-relativistic heavy-ion collisions
• Systematic Errors: facts and fictions
• Importance of non-flow in mixed-harmonic multi-particle correlations in small collision systems
• Higher harmonic non-linear flow modes of charged hadrons in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Generic algorithm for multi-particle cumulants of azimuthal correlations in high energy nucleus collisions
• Searches for transverse momentum dependent flow vector fluctuations in Pb-Pb and p-Pb collisions at the LHC
• Mixed higher-order anisotropic flow and nonlinear response coefficients of charged particles in PbPb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 2.76 and 5.02 TeV
• Signatures of collective behavior in small systems