Speaker
Description
Charm quarks are an ideal probe of the QGP created in heavy-ion collisions as they are produced at very early stages of such collisions and subsequently experience the whole evolution of the system. At STAR experiment, charm quark production can be accessed by direct topological reconstruction of open-charm hadrons thanks to an exceptional spatial resolution of the Heavy-Flavor Tracker detector.
In this poster, we will present a measurement of D$^\pm$ meson production in Au+Au collisions at $\sqrt{s_\mathrm{NN}}$ = 200 GeV by the STAR using data collected in 2014 and 2016. Supervised machine-learning techniques were used to optimize the yield extraction from the three body hadronic decay channel $\textrm{D}^\pm \rightarrow \textrm{K}^\mp \pi^\pm \pi^\pm$. The D$^\pm$ invariant spectrum was then obtained in 0-10\%, 10-40\%, 40-80\%, and 0-80\% central Au+Au collisions. The measured nuclear modification factor $R_\mathrm{AA}(p_\mathrm{T})$ reveals a significant suppression of high-$p_\mathrm{T}$ D$^\pm$ mesons in central and mid-central Au+Au collisions with respect to p+p collisions. The $(\textrm{D}^++\textrm{D}^-)/(\textrm{D}^0+\overline{\textrm{D}^0})$ yield ratio has also been extracted and compared to that from PYTHIA calculations.
