Are we seeing color (de)coherence in heavy-ion collisions?*

Jets are excellent probes of the quark-gluon plasma (QGP) produced in heavy-ion (HI) collisions because the partons inside jets interact with the medium, leading to jet energy loss and substructure modification - a phenomenon called jet quenching. Jet substructure measurements investigate how the internal structure of the jet is modified by the medium, providing insight about jet-medium interactions. In particular, observables that focus on the hard parton splittings inside the jet may tell us about color decoherence, where the medium can resolve and modify the splitting as two independent color charges. Recent jet splitting measurements in HI collisions hint that we are seeing color decoherence through the modification of these observables. This interpretation is complicated, however, because such results can also be explained by a possible change in quark/gluon fractions in HI collisions due to the expectation that gluons are more significantly modified in the medium. This talk will discuss the question of decoherence in light of recent measurements, theoretical predictions, and new Monte Carlo studies. Ideas of how to disentangle these effects will be proposed, including using electroweak boson and heavy-flavor tagged jets, especially in the context of the upcoming LHC Run 3.