How particles emerge from decaying classical fields in heavy ion collisions: towards a kinetic description of the Glasma

TL;DR

This paper develops a kinetic theory framework for the early Glasma stage in high energy heavy ion collisions, describing particle production from classical field decay via a modified Boltzmann equation.

Contribution

It introduces a Boltzmann equation with an inhomogeneous source and new collision terms to model particle emergence from classical fields in the Glasma.

Findings

Formulation of a Boltzmann equation for Glasma particles

Identification of source and collision term modifications

Outline of transition from field to particle dominance

Abstract

We develop the formalism discussed previously in hep-ph/0601209 and hep-ph/0605246 to construct a kinetic theory that provides insight into the earliest ``Glasma'' stage of a high energy heavy ion collision. Particles produced from the decay of classical fields in the Glasma obey a Boltzmann equation whose novel features include an inhomogeneous source term and new contributions to the collision term. We discuss the power counting associated with the different terms in the Boltzmann equation and outline the transition from the field dominated regime to the particle dominated regime in high energy heavy ion collisions.