Speaker
Description
Charm quarks, produced in the earliest stages of high-energy heavy-ion collisions due to their large masses, are sensitive to the full evolution of the strongly interacting medium and serve as unique probes of its collective properties. Measuring the elliptic flow ($v_{2}$) of open-charm hadrons across different collision systems provides crucial insight into the onset and strength of collectivity in QCD matter and constrains the parameters governing heavy-quark dynamics.
In this contribution, we present a comprehensive overview of charm-hadron elliptic flow measurements with the ALICE detector, offering a unified picture of charm-quark collectivity from small to large collision systems.
Measurements of $\mathrm{D^{0}}$--hadron angular correlations reveal collective-like effects even in in pp collisions at $\sqrt{s} = 13.6~\mathrm{TeV}$, challenging conventional expectations. The first measurement of charm-hadron $v_{2}$ in O--O collisions at $\sqrt{s_{\mathrm{NN}}} = 5.36~\mathrm{TeV}$ extends heavy-flavour flow studies to an intermediate system bridging pp and Pb--Pb, and offering new constraints on the charm spatial diffusion coefficient ($D_{\mathrm{s}}$). The O--O results are discussed alongside the latest Pb--Pb measurements at $\sqrt{s_{\mathrm{NN}}} = 5.36~\mathrm{TeV}$, which provide the most precise determination to date of D-meson and $\Lambda_{\mathrm{c}}$ $v_{2}$. The comparison between strange and non-strange D mesons and between mesons and baryons sheds light on the partonic origin of charm flow and the role of quark recombination in hadronization.
