Initial stage jet momentum broadening in tBLFQ formalism

TL;DR

This paper employs the light-front QCD Hamiltonian formalism to analyze the quantum evolution of a high-energy quark jet in the Glasma, revealing anisotropic momentum broadening and comparing quantum and classical approaches.

Contribution

It introduces a quantum treatment of jet evolution in the Glasma using light-front Hamiltonian formalism, advancing beyond classical probe models.

Findings

Quantitative results for jet momentum broadening and quenching parameter.

Identification of anisotropies between longitudinal and transverse directions.

Comparison between quantum and classical calculations of jet evolution.

Abstract

We study the momentum broadening of a high-energy quark jet in the large density gluon medium created right after the collision of two ultrarelativistic heavy nuclei, the Glasma. Previous Glasma studies modeled the jet as a classical probe particle, for which position and momentum are simultaneously determined. In this work, we use the light-front QCD Hamiltonian formalism to treat the jet as a fully quantum state. We compute its real-time evolution while propagating through the Glasma classical background fields, which act as an interaction potential in the quantum evolution of the jet. We present results for the momentum broadening and jet quenching parameter of a jet at mid-rapidity, with special emphasis on the anisotropies between the longitudinal and transverse directions relative to the collision axis. In addition, we compare our results to classical calculations, and initiate a study of the distinction between kinetic and canonic momentum in the context of jet momentum broadening.