D-meson production via sequential hadronization in high-energy nuclear collisions

Heavy flavor production serves as an ideal probe of the hadronization mechanism of the quark-gluon plasma created in relativistic heavy ion collisions. We study charm quark hadronization by taking Langevin equations for the charm quark transport in the medium and a sequential coalescence model for the hadronization. Since the $D_s$ formation is earlier than $D^0$, obtained from the Dirac equation with hot potential extracted from lattice QCD, the $D_s$ elliptic flow $v_2$ is smaller than the $D^0\ v_2$ in the intermediate $p_T$ region, which explains well the recent ALICE data. The sequential coalescence also predicts a hill in the yield ratio $D_s/D^0$ at low $p_T$, which can be tested in future heavy-ion collisions.