Modification of the Jet Energy-Energy Correlator in Cold Nuclear Matter

TL;DR

This paper analyzes how cold nuclear matter modifies the jet energy-energy correlator in electron-nucleus and proton-nucleus collisions, providing analytical expressions and comparing with LHC data.

Contribution

It introduces a leading-order analytical calculation of medium modifications to the EEC in cold nuclear matter, extending to gluon jets and comparing with experimental data.

Findings

Modification strongest at large angles within the jet cone

Explicit dependence on jet energy, medium scattering power, and path length

Comparison with LHC proton-lead collision data

Abstract

We compute medium corrections to the energy-energy correlator (EEC) for jets in electron-nucleus collisions at leading order in the QCD coupling and the interaction of the jet with the medium. We derive an analytical expression for the modification of the EEC as a function of the opening angle and show that the modification is strongest at large angles within the jet cone. We obtain explicit results for the dependence of the modification on the jet energy, the scattering power of cold nuclear matter, and the path length within the medium. We extend our calculations to gluon jets in proton-nucleus collisions and compare our results with recent preliminary data for proton-lead collisions at the LHC. We also discuss the role of comovers on the EEC in p+Pb collisions.