Measurements of $D^{\pm}$ meson production and total charm quark production yield at midrapidity in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200\,GeV by the STAR experiment

Abstract

Charm quarks are produced at very early stage of ultra-relativistic Au+Au collisions at RHIC top energy. This makes them an ideal probe of the Quark-Gluon Plasma, as they experience the whole evolution of the hot and dense medium. At STAR, production of charm quarks can be accessed via a direct topological reconstruction of hadronic decays of open charm hadrons, utilizing the excellent resolution of the Heavy Flavor Tracker. In these proceedings, we present measurements of D$^\pm$ meson production in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV. The invariant yields are extracted in 0-10$\%$, 10-40$\%$, and 40-80$\%$ central Au+Au collisions. The result is then used to calculate the nuclear modification factor, which reveals a strong suppression of high-$p_\mathrm{T}$ D$^\pm$ mesons in Au+Au collisions with respect to $p$+$p$ collisions. In addition, the D$^\pm$/D$^0$ yield ratio as a function of transverse momentum is calculated and compared to PYTHA 8 prediction. No significant modification of the ratio in Au+Au collisions is observed. The measurement of D$^\pm$ completed the measurements of the major ground states of open charm hadrons (D$^0$, D$^\pm$, D$_\mathrm{s}$, $\Lambda_\mathrm{c}$), that are used to calculate the total charm quark production cross section per binary nucleon-nucleon collision in 10-40$\%$ central Au+Au collisions. The measured value in Au+Au collisions is consistent with that measured in $p$+$p$ collisions.