Heavy Quark Pair Energy Correlators: From Profiling Partonic Splittings to Probing Heavy-Flavor Fragmentation

We introduce heavy-flavor energy correlators, $⟨\mathrm{\Psi }\mathrm{\mid }{\mathcal{E}}_{\mathcal{H}}({\vec{n}}_1){\mathcal{E}}_{\mathcal{H}}({\vec{n}}_2)\mathrm{\mid }\mathrm{\Psi }⟩$, as a powerful observable for profiling partonic splittings and characterizing heavy-flavor fragmentation. We present its collinear factorization, perform resummation, and demonstrate the angular distribution’s sensitivity to both the heavy-quark pair splitting and their subsequent fragmentation. We then apply the heavy-flavor EEC to probe medium-induced effects, revealing its sensitivity to medium modifications to heavy-quark pair splitting functions and to the medium’s spatial structure.