Probing the Short-Distance Structure of the Quark-Gluon Plasma through Energy-energy Correlators

Energy-energy correlators (EECs) are promising observables for probing the dynamics of jet evolution in the quark-gluon plasma (QGP). By studying jet propagation in a uniform QGP medium, we isolate and examine the individual effects of jet energy loss, jet-induced medium response, and medium-induced gluon radiation on the EECs. We find that the enhancement of EECs at large angles arises predominantly from medium response via elastic scatterings, rather than from medium-induced gluon radiation. In contrast, EECs are suppressed at small angles due to energy loss and transverse momentum broadening of the jet shower partons. We further present the first complete calculation of EECs in high-energy heavy-ion collisions using realistic simulations. These medium-induced modifications are shown to be sensitive to the angular scale of in-medium interactions, as characterized by the Debye screening mass. Experimental measurements of such modifications can thus provide insight into this scale and reveal the short-distance structure of the QGP.