Cumulants of the chiral order parameter in a nonequilibrium Bjorken expansion with a QCD critical point
Document Type
Conference Item
Publication Date
1-1-2022
Abstract
To understand experimentally obtained net-proton number cumulants in the search for the QCD critical point, we study a dynamical model based on an effective quark-meson Lagrangian with chiral symmetry. We investigate the evolution of the expanding medium created in a heavy-ion collision using a spatially homogeneous fluid and a time-dependent order parameter, the sigma field evolved by a Langevin equation. We extract cumulants of the sigma field along a parametrized freeze-out curve and match the obtained freeze-out points to corresponding beam energies. These cumulants can be related to cumulants of the net-proton number through the sigma-proton coupling to provide a qualitative comparison to experimental data from STAR's beam energy scan program. We demonstrate that the presence of the spinodal or mixed phase region around the first-order chiral phase transition allows for a wide interval of cumulants at the lowest beam energies. © 2022 Institute of Physics Publishing. All rights reserved.
Keywords
Differential equations, Heavy ions, Beam energies, Chiral symmetry, Cumulants, Dynamical modeling, Freeze out, Heavy-ion collisions, Lagrangian, Model-based OPC, Non equilibrium, Order parameter, Colliding beam accelerators
Divisions
PHYSICS
Funders
Development and Promotion of Science and Technology Talents Project,Suranaree University of Technology,Universiti Malaya [Grant no. GPF044B-2018]
Publication Title
Journal of Physics: Conference Series
Volume
2145
Issue
1
Publisher
IOP Publishing Ltd
Event Title
16th Siam Physics Congress, SPC 2021
Event Location
Virtual, Online
Event Dates
24-25 May 2021
Event Type
conference