Early thermalization of quark-gluon matter with the elastic scattering of ggq and ggqbar

TL;DR

This paper investigates the early thermalization of quark-gluon matter through elastic ggq and ggqbar scatterings, deriving transport equations and demonstrating rapid thermal state establishment in initial quark-gluon systems.

Contribution

It introduces a detailed perturbative QCD analysis of elastic ggq and ggqbar scatterings and formulates transport equations to explain early thermalization in quark-gluon matter.

Findings

Quark-gluon matter thermalizes rapidly.

Different thermalization times for gluons and quarks.

Transport equations effectively describe the thermalization process.

Abstract

Elastic gluon-gluon-quark (gluon-gluon-antiquark) scattering is studied in perturbative QCD with 123 Feynman diagrams at the tree level. Individually squared amplitudes and interference terms of the Feynman diagrams are derived. With the elastic gluon-gluon-quark scattering and the elastic gluon-gluon-antiquark scattering transport equations are established. In the thermalization process of initially created quark-gluon matter, this matter is governed by elastic 2-to-2 scattering and elastic 3-to-3 scattering. Solutions of the transport equations show that initially created quark-gluon matter takes early thermalization, i.e., thermal states are established rapidly. Different thermalization times of gluon matter and quark matter are obtained.