Toward parton equilibration with improved parton interaction matrix elements

TL;DR

This paper investigates the impact of using exact two-to-three parton interaction matrix elements, instead of approximate ones, on the thermalization process of Quark-Gluon Plasma in high-energy collisions.

Contribution

It introduces the use of exact matrix elements for parton interactions to improve understanding of Quark-Gluon Plasma equilibration, comparing results with traditional approximations.

Findings

Exact matrix elements differ significantly from Gunion-Bertsch results.

Implications for faster or more accurate thermalization modeling.

Potential influence on interpreting heavy ion collision experiments.

Abstract

The Quark-Gluon Plasma can be produced in high energy heavy ion collisions and how it equilibrates is important for the extraction of the properties of strongly interacting matter. A radiative transport model can be used to reveal interesting characteristics of Quark-Gluon Plasma thermalization. For example, screened parton interactions always lead to partial pressure isotropization. Systems with different initial pressure anisotropies evolve toward the same asymptotic evolution. In particular, radiative processes are crucial for the chemical equilibration of the system. Matrix elements under the soft and collinear approximation for these processes, as first derived by Gunion and Bertsch, are widely used. A different approach is to start with the exact matrix elements for the two to three and its inverse processes. General features of this approach will be reviewed and the results will be compared with the Gunion-Bertsch results. We will comment on the possible implications of the exact matrix element approach on Quark-Gluon Plasma thermalization.