Mixed higher-order anisotropic flow and nonlinear response coefficients of charged particles in PbPb collisions at $\sqrt{S}$$_{NN}$=2.76 and 5.02TeV

Abstract

Anisotropies in the initial energy density distribution of the quark-gluon plasma created in high energy heavy ion collisions lead to anisotropies in the azimuthal distributions of the final-state particles known as collective anisotropic flow. Fourier harmonic decomposition is used to quantify these anisotropies. The higher-order harmonics can be induced by the same order anisotropies (linear response) or by the combined influence of several lower order anisotropies (nonlinear response) in the initial state. The mixed highe-rorder anisotropic flow and nonlinear response coefficients of charged particles are measured as functions of transverse momentum and centrality in PbPb collisions at nucleon-nucleon center-of-mass energies root s(NN) = 2.76 and 5.02 TeV with the CMS detector. The results are compared with viscous hydrodynamic calculations using several different initial conditions, aswell asmicroscopic transport model calculations. None of the models provides a simultaneous description of the mixed higher-order flow harmonics and nonlinear response coefficients.Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de Maeztu: MDM-2015-0509Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de MaeztuFonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium)Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand)Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium)Janos Bolyai Research Scholarship of the Hungarian Academy of SciencesMobility Plus program of the Ministry of Science and Higher EducationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Ministry of Education, Youth and Sports (MEYS) of the Czech Republic