Heavy quark $\kappa$ and jet $\hat{q}$ transport coefficients in the Glasma early stage of heavy-ion collisions

TL;DR

This study investigates how the early-stage Glasma fields in heavy-ion collisions influence the transport properties of heavy quarks and jets, revealing large transport coefficients with characteristic peaks.

Contribution

It introduces a numerical framework combining real-time lattice gauge theory and colored particle-in-cell methods to simulate probe transport in Glasma fields, providing new quantitative insights.

Findings

Heavy quark κ and jet q̂ are large in the Glasma.

Transport coefficients exhibit a peak regardless of initial conditions.

Momentum broadening and anisotropy transfer are quantified.

Abstract

We study the impact of the Glasma fields, used to describe the very early stage of heavy-ion collisions, on the transport of hard probes, namely heavy quarks and jets. We perform numerical simulations of the strong classical fields using techniques from real-time lattice gauge theory. The resulting fields are used as background for the classical transport of ensembles of particles, described by Wong's equations. For this purpose, we develop a numerical solver for the transport of the probes, based on colored particle-in-cell methods. We focus on the dynamics of heavy quarks and jets in the classical colored fields. To quantify the effect of the Glasma, we extract the momentum broadening of hard probes and evaluate the anisotropy transfer from the Glasma to the probes. Lastly, we evaluate the heavy quark $\kappa$ and jet $\hat{q}$ transport coefficients in the Glasma, which turn out to be large and exhibit a peak, irrespective of the particle initialization.