Centrality and transverse momentum dependence of $D^0$-meson production at mid-rapidity in Au + Au collisions at $\sqrt{s_{NN}}=$ =200 GeV

We report a new measurement of $D^0$-meson production at mid-rapidity $(|y| 4 GeV/$c$ in central 0-10% Au+Au collisions. At low $p_T$, the nuclear modification factors show a characteristic structure qualitatively consistent with the expectation from model predictions that charm quarks gain sizable collective motion during the medium evolution. The improved measurements are expected to offer new constraints to model calculations and help gain further insights into the hot and dense medium created in these collisions