Abstract
We investigate the nonequilibrium evolution of the quark-meson model using two-particle irreducible effective action techniques. Our numerical simulations, which include the full dynamics of the order parameter of chiral symmetry, show how the model thermalizes into different regions of its phase diagram. In particular, by studying quark and meson spectral functions, we shed light on the real-time dynamics approaching the crossover transition, revealing e.g. the emergence of light effective fermionic degrees of freedom in the infrared. At late times in the evolution, the fluctuation-dissipation relation emerges naturally among both meson and quark degrees of freedom, confirming that the simulation successfully reaches thermal equilibrium.
Highlights
The quest to discover the conjectured critical point of the QCD phase diagram is a central motivation of modern heavy-ion collision experiments at collider facilities, such as the Large Hadron Collider at CERN and the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory
Our numerical simulations, which include the full dynamics of the order parameter of chiral symmetry, show how the model thermalizes into different regions of its phase diagram
While the time scales to converge to thermal distribution functions depend on the particle species and the momentum modes, we find that the distribution functions all become stationary for times τ ≳ 100, reflecting the timetranslation invariant property of thermal equilibrium
Summary
The quest to discover the conjectured critical point of the QCD phase diagram is a central motivation of modern heavy-ion collision experiments at collider facilities, such as the Large Hadron Collider at CERN and the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. In particular the gluons, heavier quark flavors, as well as higher mass hadronic resonances carry masses ≳500 MeV and are neglected here This low-energy effective theory reflects the central and physically relevant feature of low-energy QCD: chiral symmetry breaking in vacuum and its restoration at finite temperature and density. The evolution toward thermal equilibrium is viewed through the lens of the one- and two-point functions of the theory, which are computed with the two-particle irreducible (2PI) approach by means of their quantum equations of motion These correlation functions provide complementary order parameters for the study of chiral symmetry restoration and give direct access to the spectral properties, including the quasiparticle content of the system. We provide details about the evolution equations of the model including the relevant expressions for the deployed approximation scheme
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
