We report the first measurement of charmed-hadron ($D^0$) production via the hadronic decay channel ($D^0\rightarrow K^- + \pi^+$) in Au+Au collisions at $\sqrt{ s_{ _{ \mathrm{ NN}}}}$ = 200\,GeV with the STAR experiment. The charm production cross-section per nucleon-nucleon collision at mid-rapidity scales with the number of binary collisions, $N_{ bin}$, from $p$+$p$ to central Au+Au collisions. The $D^0$ meson yields in central Au+Au collisions are strongly suppressed compared to those in $p$+$p$ scaled by $N_{ bin}$, for transverse momenta $p_{ T}>3$ GeV/$c$, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate $p_{ T}$ is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.
Categories: nucl-ex