Adiabatic hydrodynamization in rapidly-expanding quark-gluon plasma

Understand

We propose a new scenario characterizing the transition of the quark-gluon plasma (QGP) produced in heavy-ion collisions from a highly non-equilibrium state at early times toward a fluid described by hydrodynamics at late times.

• We develop an analogy to the evolution of a quantum mechanical system that is governed by the instantaneous ground states.
• In the simplest case, these slow modes are "pre-hydrodynamic" in the sense that they are initially distinct from, but evolve continuously into, hydrodynamic modes.
• For a class of collision integrals, the pre-hydrodynamic mode represents the angular distribution (in momentum space) of those gluons that carry most of the energy.