Sensitivity of Au+Au collisions to the symmetric nuclear matter equation of state at 2–5 nuclear saturation densities

【Abstract】
We demonstrate that proton and pion flow measurements in heavy-ion collisions at incident energies ranging from 1 to 20 GeV per nucleon in the fixed target frame can be used for an accurate determination of the symmetric nuclear matter equation of state at baryon densities equal 2–4 times nuclear saturation density n0. We simulate Au+Au collisions at these energies using a hadronic transport model with an adjustable vector mean-field potential dependent on baryon density nB. We show that the mean field can be parametrized to reproduce a given density dependence of the speed of sound at zero temperature cs2(nB,T=0), which we vary independently in multiple density intervals to probe the differential sensitivity of heavy-ion observables to the equation of state at these specific densities. Recent flow data from the STAR experiment at the center-of-mass energies sNN={3.0,4.5}GeV can be described by our model, and a Bayesian analysis of these data indicates a hard equation of state at nB∈(2,3)n0 and a possible phase transition at nB∈(3,4)n0. More data at sNN=2–5GeV, as well as a more thorough analysis of the model systematic uncertainties will be necessary for a more precise conclusion.

【Author】
Dmytro Oliinychenko, Agnieszka Sorensen, Volker Koch, Larry McLerran

【Journal】
Physical Review C(IF：3.1) Time：2023-09-20