Advancing the understanding of energy-energy correlators in heavy-ion collisions
João Barata🇺🇸 · Paul Caucal🇫🇷 · Alba Soto-Ontoso🇨🇭 · Robert Szafron🇺🇸
We investigate the collinear limit of the energy-energy correlator (EEC) in a heavy-ion context. First, we revisit the leading-logarithmic (LL) resummation of this observable in vacuum following a diagrammatic approach. We argue that this route allows to naturally incorporate medium-induced effects into the all-orders structure systematically. As an example, we show how the phase-space constraints imposed by the medium on vacuum-like emissions can be incorporated into the LL result by modifying the anomalous dimensions. On the fixed-order side, we calculate the expansion of the in-medium EEC for a splitting using, for the first time, the exact matrix element. When comparing this result to previously used approximations in the literature, we find up to deviations in the regime of interest for jet quenching signatures. Energy loss effects are also quantified and further suppress the EEC at large angles. These semi-analytic studies are complemented with a phenomenological study using the jet quenching Monte Carlo JetMed. Finally, we argue that the imprint of medium-induced effects in energy-energy correlators can be enhanced by using an alternative definition that takes as input Lund primary declusterings instead of particles.