Deriving a parton shower for jet thermalization in QCD plasmas

TL;DR

This paper introduces a new parton-shower algorithm that accurately models jet thermalization in QCD plasmas, incorporating key microscopic processes from effective kinetic theory.

Contribution

The authors develop a novel parton-shower framework that precisely reproduces linearized effective kinetic theory dynamics, improving the modeling of jet thermalization in heavy-ion collisions.

Findings

The new algorithm captures recoils, holes, and quantum statistics.

It enables first-principles simulations of jet-medium interactions.

The approach improves understanding of equilibration in QCD plasmas.

Abstract

Jet quenching - the modification of high-energy jets in the quark-gluon plasma - has been extensively studied through weakly coupled scattering amplitudes embedded in parton-shower frameworks. These models, often combined with bulk hydrodynamic evolution, successfully describe a wide range of observables, though they typically rely on assumptions of rapid thermalization and simplified treatments of medium response. Parallel to these developments, jet thermalization has been investigated within the finite-temperature QCD effective kinetic theory, which provides our best microscopic understanding of equilibration in heavy-ion collisions. Early studies of linearized perturbations have highlighted both the promise and the limitations of current approaches, as existing MC implementations face challenges - particularly in the treatment of recoils and particle merging. Building on this foundation, we introduce a new parton-shower algorithm that exactly reproduces the dynamics of the linearized EKT, enabling a first-principles description of jet thermalization with proper inclusion of recoils, holes, quantum statistics, and merging processes.