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

¹ Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada
² Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201, USA
³ RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973, USA

^* e-mail: lipei.du@mail.mcgill.ca
^** e-mail: chunshen@wayne.edu
^*** e-mail: sangyong.jeon@mcgill.ca
^**** e-mail: charles.gale@mcgill.ca

Published online: 26 June 2024

Abstract

Our investigation focuses on the rapidity-dependent directed flow, v₁(y), of identified hadrons in Au+Au collisions across a broad range of √S_NN from 7.7 to 200 GeV. Employing a (3+1)-dimensional hybrid framework, our study successfully reproduces the characteristic features of the measured v₁(y) for both mesons and baryons across the considered beam energies. Notably, our analysis reveals the constraining power of baryonic v₁(y) on the initial baryon stopping mechanism. Together with mesonic v₁(y), the directed flow serves as a crucial tool for probing the equation of state governing dense nuclear matter at finite chemical potentials.