Chekhovsky, V.Hayrapetyan, A.Makarenko, V.Tumasyan, A.Adam, W.Andrejkovic, J. W.Benato, L.2026-04-252026-04-2520250370-26931873-2445https://doi.org/10.1016/j.physletb.2025.139556https://hdl.handle.net/11486/8312Energy-energy correlators are constructed by averaging the number of charged particle pairs within jets, weighted by the product of their transverse momenta, as a function of the angular separation of the particles within a pair. They are sensitive to a multitude of perturbative and nonperturbative quantum chromodynamics phenomena in high-energy particle collisions. Using lead-lead data recorded with the CMS detector, energy-energy correlators inside high transverse momentum jets are measured in heavy ion collisions for the first time. The data are obtained at a nucleon-nucleon center-of-mass energy of 5.02TeV and correspond to an integrated luminosity of 1.70 nb(-1). A similar analysis is done for proton-proton collisions at the same center-of-mass energy to establish a reference. The ratio of lead-lead to proton-proton energy-energy correlators reveals significant jet substructure modifications in the quark-gluon plasma. The results are compared to different models that incorporate either color coherence or medium response effects, where the two effects predict similar substructure modifications.eninfo:eu-repo/semantics/openAccessCMSJetsEnergyResolutionCorrelatorArticle86610.1016/j.physletb.2025.139556Q1WOS:001511646400001Q10000-0003-1609-35150000-0002-8298-75600000-0003-4420-55100000-0003-4540-90480000-0002-3293-37590000-0003-4540-90480000-0002-6665-7289