Sirunyan, A. M.Tumasyan, A.Adam, W.Ambrogi, F.Asilar, E.Bergauer, T.Brandstetter, J.2025-03-232025-03-2320202469-99852469-9993https://doi.org/10.1103/PhysRevC.101.014912https://hdl.handle.net/11486/5630The second- and third-order azimuthal anisotropy Fourier harmonics of charged particles produced in pPb collisions, at root s(NN) = 8.16 TeV, are studied over a wide range of event multiplicities. Multiparticle correlations are used to isolate global properties stemming from the collision overlap geometry. The second-order elliptic harmonic moment is obtained with high precision through four-, six-, and eight-particle correlations and, for the first time, the third-order triangular harmonic moment is studied using four-particle correlations. A sample of peripheral PbPb collisions at root s(NN) = 5.02 TeV that covers a similar range of event multiplicities as the pPb results is also analyzed. Model calculations of initial-state fluctuations in pPb and PbPb collisions can be directly compared to the high-precision experimental results. This work provides new insight into the fluctuation-driven origin of the v(3) coefficients in pPb and PbPb collisions, and into the dominating overall collision geometry in PbPb collisions at the earliest stages of heavy ion interactions.eninfo:eu-repo/semantics/openAccessSide Angular-CorrelationsPb-Pb CollisionsLong-RangeFlowCollectivityProtonArticle101110.1103/PhysRevC.101.0149122-s2.0-85078836395Q1WOS:000509493400006Q2