The VII-th International Conference on the Initial Stages of High-Energy Nuclear Collisions : Initial Stages 2023

Quantum to classical parton evolution in the QGP

Not scheduled

20m

Copenhagen

Oral The initial stages and nuclear structure in heavy-ion collisions

Speaker

João Barata

Description

At leading order, the evolution of a particle in the quark gluon plasma will result in the broadening of its transverse momentum. At the level of the particle distribution, this process admits a completely classical description, where the evolution in transverse momentum space can be understood as a diffusive process. However, the full evolution of the parton in the medium is sensitive to kinetic quantum phases, which do not contribute to observables related to the particle distribution. In this talk we will present a formulation of parton evolution in the medium at the density matrix level which allows to capture the full quantum evolution of the system. We show that the quantum phases control the evolution of off-diagonal elements of the density matrix are responsible for the emergence of a classical picture for it at late times. In addition, we find an analogy between the evolution of the quark's density matrix and gluon production in the medium, being able to make a clear connection to the LPM effect. Finally, we show that the associated entropy rate increases at late times.