Measurements of open charm production and flow in √s_NN = 200GeV Au+Au collisions with the STAR experiment at RHIC

Department of Physics, Kent State University, Ohio 44242, USA

^* e-mail: smargeti@kent.edu

Published online: 14 November 2018

Abstract

We present an improved, higher statistics, measurement with respect to the previously published results of the D⁰ meson elliptic flow (v₂) as a function of transverse momentum (p_T) in Au+Au collisions at √s_NN = 200 GeV with the STAR Heavy Flavor Tracker (HFT). The D⁰ v₂ results are compared to those of light-flavor hadrons to test the number-of-constituent-quark (NCQ) scaling. They are also compared to recent hydrodynamic and transport model calculations. We also report on the updated measurements of D⁰ nuclear modification factors R_AA and R_CP using the 2014 data. The measured D⁰ R_AAin central collisions is less than 1 across the entire p_T region. The D⁰ yields show strong suppression at high p_T (> 6 GeV/c) in central collisions, consistent with those of light flavor hadrons.

We also report the measurements of collision centrality and p_T dependences of the Λ^±_c production in Au+Au collisions at √s_NN = 200 GeV, using the HFT. The Λ^±_c signal significance is greatly improved with the addition of the highstatistics data set collected in 2016 and the use of a supervised machine learning method for a more effcient topological reconstruction of the decay vertices. The measured Λ^±_c/D⁰ ratio in 10-80% Au+Au collisions shows a significant enhancement compared to the PYTHIA prediction for p + p collisions, across the measured p_T range.