Quark Matter 2025

Beam Energy Dependence of Baryon Directed Flow (v1) in Au + Au Collision at RHIC-STAR

Not scheduled

20m

Goethe University Frankfurt, Campus Westend, Theodor-W.-Adorno-Platz 1, 60629 Frankfurt am Main, Germany

Poster Collective dynamics & small systems Poster session 2

Speaker

Zhuo Wang

Description

Anisotropic collective flow provides valuable information about the evolution of nuclear matter in the early stages of collisions and is one of the commonly used observables in high-energy heavy ion collisions. The first harmonic coefficient in the Fourier expansion of the
final-state azimuthal anisotropy, relative to the reaction plane, is referred to as directed flow, $v_1$.The $v_1$ slope with respect to the rapidity for net-baryons from the first phase of Beam Energy Scan (BES-I) exhibits a minimum around 10-20 GeV, a feature predicted to be sensitive to the softening of the equation of state
near a first-order phase transition.

In this poster, we will present the rapidity dependence of $p$ , $\overline{p}$ , $\mathrm{\Lambda }$ and $\overline{\mathrm{\Lambda }}$ $v_1$ in Au + Au collisions at $\sqrt{s_{NN}}=7.7$, 9.2, 11.5, 14.5, 17.3, and 19.6 GeV using the high statistics data from the Beam Energy Scan Phase II
(BES-II) by STAR.We will compare our measurements with transport model calculations
and discuss the implications for understanding the QCD phase structure.

Presentation materials

QM2025_poster_STAR_ver5.pdf