We report the first measurement of $\Lambda_c^+$ (average of $\Lambda_c^+$ and $\bar{ \Lambda}_c^-$) baryon production and significantly improved measurement of $D_s^+$ (average of $D_s^+$ and $D_s^-$) meson production, within the rapidity range of $\left|y\right| < 1$ in Au+Au collisions at $\sqrt{ s_{ \rm NN}}$ = 200 GeV from the STAR experiment. The transverse momentum spectra of $\Lambda_c^+$ and $D_s^+$ as well as their yield ratios to that of $D^0$ meson are also presented and compared to theoretical calculations.Both the $\Lambda_c^+/D^0$ and $D_s^+/D^0$ ratios are found to be significantly enhanced in Au+Au collisions with respect to those in p+p collisions predicted by PYTHIA. A model calculation including coalescence hadronization and thermalized charm quarks is consistent with the measured $\Lambda_c^+/D^0$ ratio. On the other hand, the TAMU model seems to underestimate the $D_s^+/D^0$ ratio measured in Au+Au collisions in the applicable kinematic region.
Categories: nucl-ex