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Energy-energy correlators inside single inclusive jets in heavy-ion collisions with the CoLBT-hydro model

Zhong Yang1, Raghav Kunnawalkam Elayavalli1, and Xin-Nian Wang2

Phys. Rev. C 114, 034914 – Published 21 September, 2026

DOI: https://doi.org/10.1103/zpvs-4x68

Abstract

The energy-energy correlator (EEC) inside jets is a sensitive observable for studying jet modification in the quark-gluon plasma. However, its interpretation in heavy-ion collisions remains challenging, requiring a consistent understanding of jet evolution across multiple dynamical scales together with a proper treatment of the background subtraction. In this work, we employ an updated CoLBT-hydro framework in which a medium scale QM=2.0 GeV is introduced to separate the vacuum and in-medium stages of the parton shower, enabling a more self-consistent treatment of jet evolution. Using a theoretical background subtraction within the model, the resulting simulation reproduces the recent CMS measurement of the in-jet EEC and, through a decomposition of the different contributions, highlights the impact of medium modification on the observable. To further validate the experimental procedure, we also implement the CMS mixed-event background-subtraction method directly in the simulation and find that the results are consistent with those obtained with the theoretical background subtraction. Using pT-ranked jets in each event, we further investigate the dependence of medium modification on the in-medium path length, reflected in the different EECs of leading and subleading jets. Finally, we explore the dependence of the leading-jet EEC on the dijet rapidity gap as a signal of the jet-induced diffusion wake.

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