Speaker
Description
Directed flow ($v_{1}$) describes the collective sideward motion of produced particles and nuclear fragments in heavy-ion collisions. The pseudorapidity ($\eta$) dependence of $v_{1}$ can provide unique constraints on the initial conditions and dynamical evolution of the Quark Gluon Plasma (QGP). Directed flow in both spectator and participant regions is sensitive to early non-equilibrium dynamics and may provide insights into the baryon stopping mechanism. In 2018, the Event Plane Detector (EPD, $2.1 < |\eta| < 5.1$) was installed in STAR and used for the Beam Energy Scan phase-II (BES-II) data taking. The combination of EPD and high statistics BES-II data enables us to extend the $v_{1}$ measurement to a wide $\eta$ range. In this talk, I will discuss the techniques for measuring $v_{1}$ with a scintillator detector like EPD, present $v_{1}$ over ten units of $\eta$ in Au+Au collisions at $\sqrt{s_{NN}}=27$ GeV and compare the results with the UrQMD model.
| Theory / experiment | Experiment |
|---|---|
| Group or collaboration name | STAR Collaboration |
