Nonequilibrium Attractor in High-Temperature QCD Plasmas

Dekrayat Almaalol,Aleksi Kurkela,Michael Strickland

doi:10.1103/physrevlett.125.122302

Abstract

We establish the existence of a far-from-equilibrium attractor in weakly coupled gauge theory undergoing one-dimensional Bjorken expansion. We demonstrate that the resulting far-from-equilibrium evolution is insensitive to certain features of the initial condition, including both the initial momentum-space anisotropy and initial occupancy. We find that this insensitivity extends beyond the energy-momentum tensor to the detailed form of the one-particle distribution function. Based on our results, we assess different procedures for reconstructing the full one-particle distribution function from the energy-momentum tensor along the attractor and discuss implications for the freeze-out procedure used in the phenomenological analysis of ultrarelativistic nuclear collisions.

Highlights

Fluid-dynamic description is a powerful tool in the phenomenological analysis of ultrarelativistic nuclear collisions [1,2,3]
We demonstrate that the resulting far-from-equilibrium evolution is insensitive to certain features of the initial condition, including both the initial momentumspace anisotropy and initial occupancy
As the freeze-out procedure strongly affects the phenomenological analysis and conclusions about the matter created in ultrarelativistic heavy-ion collisions, it is of great interest to scrutinize quantitatively how well justified are the theoretical assumptions about the shape of the nonequilibrium distribution functions

Summary

Introduction

Fluid-dynamic description is a powerful tool in the phenomenological analysis of ultrarelativistic nuclear collisions [1,2,3]. We assess different procedures for reconstructing the full one-particle distribution function from the energy-momentum tensor along the attractor and discuss implications for the freeze-out procedure used in the phenomenological analysis of ultrarelativistic nuclear collisions.

Results

Conclusion