Feb 5 – 11, 2017
Hyatt Regency Chicago
America/Chicago timezone

$\Lambda_{c}^+$ production in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV at the STAR experiment

Feb 11, 2017, 10:20 AM
Hyatt Regency Chicago

Hyatt Regency Chicago

151 East Wacker Drive Chicago, Illinois, USA, 60601


Guannan Xie (LBNL/USTC)


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. $\Lambda_{c}^+$ is the lightest charmed baryon with the mass close to $D^0$ meson, and it has an extremely short life time ($c\tau\sim60$ $\mu m$). Different models predict different levels of enhancement in the $\Lambda_{c}^+$/$D^0$ 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 $\Lambda_{c}^+$ production in heavy-ion collisions using the recently installed Heavy Flavor Tracker at STAR. $\Lambda_{c}^+$ are reconstructed through the hadronic decay channel ($\Lambda_{c}^+$ $\rightarrow$ $pK\pi$) 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 $\Lambda_{c}^+$ in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV will be presented. The measured $\Lambda_{c}^+$/$D^0$ ratio will be compared with different model calculations, and the physics implications will be discussed.

Presentation materials