Constraints on initial baryon stopping and equation of state from directed flow

TL;DR

This study uses a hybrid model to analyze the rapidity-dependent directed flow of identified hadrons in Au+Au collisions, providing insights into baryon stopping and the nuclear matter equation of state across a wide energy range.

Contribution

It demonstrates the effectiveness of directed flow measurements in constraining initial baryon stopping and the equation of state in heavy-ion collisions.

Findings

Successfully reproduces $v_1(y)$ for mesons and baryons across energies.

Shows baryonic $v_1(y)$ constrains initial baryon stopping.

Highlights $v_1(y)$ as a probe for the nuclear matter equation of state.

Abstract

Our investigation focuses on the rapidity-dependent directed flow, $v_1(y)$, of identified hadrons in Au+Au collisions across a broad range of $\sqrt{s_{\rm NN}}$ from 7.7 to 200 GeV. Employing a (3+1)-dimensional hybrid framework, our study successfully reproduces the characteristic features of the measured $v_1(y)$ for both mesons and baryons across the considered beam energies. Notably, our analysis reveals the constraining power of baryonic $v_1(y)$ on the initial baryon stopping mechanism. Together with mesonic $v_1(y)$, the directed flow serves as a crucial tool for probing the equation of state governing dense nuclear matter at finite chemical potentials.