Aad, G.Abbott, B.Abbott, D. C.Abud, A. AbedAbeling, K.Abhayasinghe, D. K.Çetin, Serkant Ali2024-07-182024-07-1820212469-99852469-9993https://doi.org/10.1103/PhysRevC.104.014903https://hdl.handle.net/11411/7648Two-particle long-range azimuthal correlations are measured in photonuclear collisions using 1.7 nb(-1) of 5.02 TeV Pb+Pb collision data collected by the ATLAS experiment at the CERN Large Hadron Collider. Candidate events are selected using a dedicated high-multiplicity photonuclear event trigger, a combination of information from the zero-degree calorimeters and forward calorimeters, and from pseudorapidity gaps constructed using calorimeter energy clusters and charged-particle tracks. Distributions of event properties are compared between data and Monte Carlo simulations of photonuclear processes. Two-particle correlation functions are formed using charged-particle tracks in the selected events, and a template-fitting method is employed to subtract the nonflow contribution to the correlation. Significant nonzero values of the second-and third-order flow coefficients are observed and presented as a function of charged-particle multiplicity and transverse momentum. The results are compared with flow coefficients obtained in proton-proton and proton-lead collisions in similar multiplicity ranges, and with theoretical expectations. The unique initial conditions present in this measurement provide a new way to probe the origin of the collective signatures previously observed only in hadronic collisions.eninfo:eu-repo/semantics/openAccessHeavy-Ion CollisionsPp CollisionsMultiplicityDetectorLhcDistributionsFluctuationsPerformanceSystemModelArticle2-s2.0-8511028742210.1103/PhysRevC.104.0149031Q1104Q2WOS:000672773000006