Multicomponent second-order dissipative relativistic hydrodynamics with binary reactive collisions

TL;DR

This paper develops second-order dissipative relativistic hydrodynamics for multi-component systems with reactive collisions, analyzing how multiple components and collision types influence transport properties and relaxation times.

Contribution

It introduces a multi-component second-order hydrodynamic framework incorporating reactive collisions and computes transport coefficients using both hard-sphere and perturbative QCD interactions.

Findings

Reactive collisions decrease transport coefficients and relaxation times.

Multi-component systems exhibit different current relaxation time to conductivity ratios than single-component systems.

Transport properties depend significantly on the type of microscopic cross-sections used.

Abstract

We derive the multi-component second-order dissipative relativistic hydrodynamic equations using the moment-expansion method. By computing the transport coefficients using hard-sphere interactions, we investigate the role of multiple components and the reactive collisions. We find that both of these factors increase the effective cross-section and hence decrease the transport coefficients and relaxation times. We further compute such transport properties using leading-order perturbative QCD cross-sections. For both types of cross-sections, we find that the ratio between vector current relaxation time and conductivity for a multi-component fluid is notably different from that for a single-component fluid. Therefore, the current study provides a more applicable guideline for such a ratio in phenomenological hydrodynamics simulations.