Non-local high-$p_t$ transport in anisotropic QCD matter

TL;DR

This paper introduces a non-local transport equation for high-$p_t$ partons in anisotropic QCD matter, showing it improves the description of jet evolution compared to traditional Boltzmann approaches.

Contribution

It derives and numerically implements a non-local master equation from QFT, extending classical transport models to better describe jet quenching in structured QCD matter.

Findings

Non-local kernel is essential for azimuthal momentum distribution.

Non-local transport captures jet structure in hydrodynamic backgrounds.

Seamless integration into existing transport codes is feasible.

Abstract

We perform a numerical study of non-local partonic transport in anisotropic QCD matter, relevant to the evolution of hard probes in the aftermath of high-energy nuclear scattering events. The recently derived master equation, obtained from QFT considerations, differs from Boltzmann transport by incorporating a non-local elastic scattering kernel arising from density gradients. After rewriting the master equation in a form suitable for numerical implementation and assuming a static density profile, we compare the non-local evolution to Boltzmann transport, demonstrating that the new interaction kernel is essential for accurately describing the azimuthal structure of the final-state momentum distribution. We further study the non-local partonic transport in the case of a matter profile governed by two-dimensional hydrodynamics, accounting for its flow and generalizing the evolution equation. Our results demonstrate the necessity of going beyond classical transport at high-$p_t$ to accurately capture the structure of jets propagating through structured QCD matter. The master equation used in the numerical simulations can be seamlessly integrated into state-of-the-art transport codes.