Thermalization in collisions of large nuclei at high energies

TL;DR

This paper explores the process of thermalization in ultrarelativistic heavy ion collisions within the framework of weak-coupling QCD, highlighting the role of plasma instabilities in the early stages.

Contribution

It provides a theoretical description of thermalization in large nuclei at high energies using weak-coupling QCD, emphasizing plasma instabilities as the dominant mechanism.

Findings

Thermalization occurs rapidly due to plasma instabilities.

The system reaches near-equilibrium at time t ~ α^(-5/2)Q^(-1).

Weak-coupling QCD describes the early dynamics effectively.

Abstract

Hydrodynamical analysis of experimental data of ultrarelativistic heavy ion collisions seems to indicate that the hot QCD matter created in the collisions thermalizes very quickly. Theoretically, we have no idea why this should be true. In this proceeding, I will describe how the thermalization takes place in the most theoretically clean limit -- that of large nuclei at asymptotically high energy per nucleon, where the system is described by weak-coupling QCD. In this limit, plasma instabilities dominate the dynamics from immediately after the collision until well after the plasma becomes nearly in equilibrium at time t \alpha^(-5/2)Q^(-1).