Recently, teams from Central China Normal University and Shandong University have made significant progress in the theoretical studies of jets in high-energy heavy-ion collisions. The findings, titled "Flavor Hierarchy of Jet Energy Correlators inside the Quark-Gluon Plasma," were published in Physical Review Letters on February 5, 2025. This work was collaboratively completed by Wenjing Xing, a postdoctoral fellow at Shandong University (a 2022 Ph.D. graduate from Central China Normal University), Professor Shanshan Cao from Shandong University, and Professors Guangyou Qin and Xin-Nian Wang from Central China Normal University.

In high-energy nucleon or nucleus collisions, high-energy quarks and gluons are produced, which become detectable hadrons (i.e., jets) through parton showering and fragmentation. Quantum Chromodynamics (QCD) predicts that small angle showering process of heavy quarks is suppressed due to quark’s mass, a phenomenon known as the "dead-cone effect." In 2022, the LHC-ALICE team, using iterative clustering techniques, analyzed the splitting vertices and angles of D-meson jets and inclusive jets in proton-proton collisions, observing the dead-cone effect of charm quarks for the first time. This achievement was published in Nature. However, the impact of the quark-gluon plasma on the dead-cone effect in the more complex environment of heavy-ion collisions remains to be further explored.

Recently, jet energy correlators have garnered significant attention due to their sensitivity to physics at different scales. This work, based on the linear Boltzmann transport (LBT) model, is the first to dynamically simulate the interaction between light/heavy flavor jets and the quark-gluon plasma in heavy-ion collisions, systematically calculating the two-particle energy correlation functions inside jets. The results show that the energy correlation strength of heavy-flavor jets is generally weaker than that of light-flavor jets due to the dead-cone effect, and the correlation peak shifts toward larger angles. Compared to proton-proton collisions, jet energy correlations in heavy-ion collisions exhibit unique nuclear modifications: suppression at intermediate angles and enhancement at small and large angles. The findings reveal rich physical processes such as mass effects, energy loss, bremsstrahlung, and medium response in the interaction between jets and the hot dense medium, providing a new approach to exploring the properties of strongly interacting matter in relativistic heavy-ion collisions. The numerical simulations and calculations for this study were primarily conducted at the Nuclear Science Computing Center (NSC3) of Central China Normal University, with support from the National Natural Science Foundation of China and the China Postdoctoral Science Foundation.

Article Link:https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.052301