The ability to measure detailed aspects of the substructure of high energy jets passing through the quark-gluon plasma (QGP) has provided a completely new probe of its internal dynamics and of QCD. However, drawing robust conclusions from traditional jet substructure observables has been difficult. This is for two main reasons, one practical and one theoretical. The environment of a heavy ion collision is messy and traditional approaches to jet substructure often find that the backgrounds are largest in the regions of phase-space most sensitive to the QGP dynamics. Compounding this problem, the QGP has complicated multi-scale dynamics. Disentangling these scales has proved difficult for theorists, indeed debate still persists over the most basic mechanisms through which a jet interacts with the QGP.
This talk presents a new approach to jet substructure in heavy ion collisions based on the study of correlation functions of energy flow operators (energy correlators). We show that the energy correlators allow us to robustly identify the scales of the QGP, as well as to observe the onset of color coherence and facilitate the study of quenched heavy flavour jets. This talk is structured for a broad QCD audience and will overview key theoretical developments in energy correlators more generally.
