Energy-energy correlators and color decoherence from a generating functional

Abstract

Using jet calculus at leading-logarithmic accuracy, we develop a generating-functional approach to describe the hard-collinear sector of jets propagating through the quark-gluon plasma. This framework yields coupled evolution equations for the jet nuclear modification factor and energy-energy correlators (EECs). We first construct the EEC evolution in the fully incoherent regime, and then derive evolution equations that account for the transition from the coherent to the incoherent limit in the large-$N_c$ limit. Furthermore, we show that combining the EEC with the jet nuclear modification factor provides complementary sensitivity to the overall jet suppression and to medium-induced modifications of the jet's internal structure. This framework therefore offers a way to constrain the magnitude and flavor dependence of jet energy loss, together with the medium resolution angle governing color decoherence.