Probing the Quark-Gluon Plasma through p_{T}-Differential Radial Flow of Heavy Quarks

We introduce the p_{T}-differential radial flow v_{0}(p_{T}) in the heavy-quark sector. Within an event-by-event Langevin framework, we show that this observable exhibits a strong sensitivity to the heavy quark-bulk interaction. It provides a powerful and novel tool to constrain the transport coefficients of heavy quarks in the quark-gluon plasma and, more generally, to assess the strength of the interaction of a Brownian particle in an expanding bulk medium. The results further indicate that heavy quarks exhibit collective behavior driven by the isotropic expansion of the quark-gluon plasma in heavy-ion collisions and, at low p_{T}, it offers a marked signature of the heavy-quark hadronization mechanism.