Effective kinetic description of event-by-event pre-equilibrium dynamics in high-energy heavy-ion collisions

Understand

We develop a macroscopic description of the space-time evolution of the energy-momentum tensor during the pre-equilibrium stage of a high-energy heavy-ion collision.

• Based on a weak coupling effective kinetic description of the microscopic equilibration process (\`a la "bottom-up"), we calculate the non-equilibrium evolution of the local background energy-momentum tensor as well as the non-equilibrium linear response to transverse energy and momentum perturbations for realistic boost-invariant initial conditions for heavy ion collisions.
• We demonstrate how this framework can be used on an event-by-event basis to propagate the energy momentum tensor from far-from-equilibrium initial state models, e.g.
• IP-Glasma, to the time $\tau_\text{hydro}$ when the system is well described by relativistic viscous hydrodynamics.