Initial stage jet momentum broadening in tBLFQ formalism

¹ Department of Physics, University of Jyväskylä, P.O. Box 35, 40014 University of Jyväskylä, Finland
² Helsinki Institute of Physics, P.O. Box 64, 00014 University of Helsinki, Finland
³ Instituto Galego de Fisica de Altas Enerxias (IGFAE), Universidade de Santiago de Compostela, 15705 Galicia, Spain

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Published online: 5 November 2025

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 canonical momentum in the context of jet momentum broadening.