Speaker
Description
Since heavy quarks are predominantly created in the initial hard scatterings in a heavy-ion collision, they can access the information of the early time dynamics. Recently, it has been predicted that the transient magnetic field generated in heavy-ion collisions can induce a larger directed flow ($v_{1}$) for heavy quarks than for light quarks. The model calculation also suggests opposite signs of $dv_{1}/dy$ for charm ($c$) and anti-charm ($\bar{c}$) quarks. This argues for heavy quarks offering a new approach to study the initial electromagnetic field. Furthermore, recent measurements at RHIC have shown that $D^{0}$ mesons in minimum bias and mid-central heavy-ion collisions exhibit significant elliptic ($v_{2}$) and triangular flow ($v_{3}$). Their flow magnitude follows the Number-of-Constituent-Quark (NCQ) scaling with light hadrons' in mid-central collisions. It will be particularly interesting to measure the centrality dependence of these observables and test whether and when the NCQ scaling breaks for charm hadrons.
STAR has collected high statistics data for Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV with the Heavy Flavor Tracker detector during 2014 and 2016, allowing us to achieve high precision anisotropic flow measurements for charm hadrons at RHIC energies. In this talk, we will report the first measurement of $v_{1}$ for the $D^{0}(\bar{u}c)$ and $\overline{D^{0}}(u\bar{c})$ mesons at $\sqrt{s_{\rm NN}}$ = 200 GeV Au+Au collisions and compare to those of light flavor hadrons and model predictions. We will present differential measurements of $D^{0}$ meson $v_{2}$ and $v_{3}$ in various centralities of Au+Au collisions, and compare them to those of light flavor hadrons to test the NCQ scaling. The $D^{0}$ $v_{2}$ measured in Au+Au collisions will also be compared to that measured in d+Au collisions to help understand the non-flow effects. Physics implications of these measurements will be discussed.
| Content type | Experiment |
|---|---|
| Collaboration | STAR |
| Centralised submission by Collaboration | Presenter name already specified |
