Jet Energy-Energy Correlator in Cold QCD Matter

Abstract: We present a study of medium-induced modifications to the energy-energy correlator (EEC) for jets in cold nuclear matter. For electron-nucleus collisions, at leading order in the QCD coupling and in the jet-medium interaction, we derive an analytic expression for the EEC modification as a function of the opening angle and show that the modification is strongest at large angles within the jet cone. The dependence on jet energy, the transport properties of cold nuclear matter, and the in-medium path length is made explicit. We further extend the analysis to gluon jets in proton-nucleus collisions and compare with preliminary proton-lead data from the LHC. Possible effects of comovers on the EEC in proton-nucleus collisions are also discussed.