Quark Matter 2017

Λc+ production in Au+Au collisions at sNN = 200 GeV at the STAR experiment

Not scheduled

2h 30m

Hyatt Regency Chicago

Board: G15

Poster Poster Session

Speaker

Guannan Xie (LBNL/USTC)

Description

Charm quarks, predominantly produced in the early stage of heavy-ion collisions, are believed to provide unique information on the hot and dense medium created in such collisions. At RHIC, an enhancement in baryon-to-meson ratios for light hadrons and hadrons containing strange quarks has been observed in central heavy-ion collisions compared to p+p and peripheral heavy-ion collisions in the intermediate $p_T$ range (2 < $p_T$ < 6 GeV/c). This was explained by the hadronization mechanism involving multi-parton coalescence. ${\mathrm{\Lambda }}_c^{+}$ is the lightest charmed baryon with the mass close to $D^0$ meson, and it has an extremely short life time ($c\tau \sim 60$ $\mu m$). Different models predict different levels of enhancement in the ${\mathrm{\Lambda }}_c^{+}$/$D^0$ ratio depending on the degree of charm quark thermalization in the medium and how the coalescence mechanism is implemented.

In this poster, we will report the first measurement of ${\mathrm{\Lambda }}_c^{+}$ production in heavy-ion collisions using the recently installed Heavy Flavor Tracker at STAR. ${\mathrm{\Lambda }}_c^{+}$ are reconstructed through the hadronic decay channel (${\mathrm{\Lambda }}_c^{+}$ $\to$ $pK\pi$) using topological cuts optimized by the Toolkit for Multivariate Data Analysis (TMVA). After correcting for the reconstruction efficiency and acceptance, the transverse-momentum spectrum of ${\mathrm{\Lambda }}_c^{+}$ in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV will be presented. The measured ${\mathrm{\Lambda }}_c^{+}$/$D^0$ ratio will be compared with different model calculations, and the physics implications will be discussed.

Presentation materials

GuannanXie_Lc_Poster_QM17_v6.pdf