Derivation of transient relativistic fluid dynamics from the Boltzmann equation for a multi-component system

TL;DR

This paper derives a new non-equilibrium distribution function for a hadron resonance gas from the Boltzmann equation and explores its implications for the freeze-out process in relativistic heavy ion collision models, comparing it with traditional methods.

Contribution

It introduces a novel derivation of the non-equilibrium distribution function for a multi-component system from the Boltzmann equation, enhancing the accuracy of freeze-out descriptions.

Findings

New distribution function derived from Boltzmann equation

Comparison shows differences with 14-moment approximation

Potential improvements in modeling heavy ion collisions

Abstract

We derive the non-equilibrium single-particle momentum distribution function of a hadron resonance gas. We then study the effects that this newly derived expression can have in the freeze-out description of fluid-dynamical models of heavy ion collisions and compare it with the method traditionally employed, the 14-moment approximation.