Towards a fluid-dynamic description of an entire heavy-ion collision: From the colliding nuclei to the quark-gluon plasma phase

¹ Department of Physics, Duke University, Durham, NC 27708, USA
² GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
³ Università di Firenze and INFN Sezione di Firenze, 50019 Sesto Fiorentino, Italy
⁴ Friedrich-Schiller-Universität Jena, 07743 Jena, Germany

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 17 April 2026

Abstract

The fluid-dynamical modeling of a nuclear collision at high energy usually starts shortly after the collision. A major source of uncertainty comes from the detailed modeling of the initial state. While the collision itself likely involves far-from-equilibrium dynamics, it is not excluded that a fluid theory of second order can reasonably well describe its soft features. Here we explore this possibility and discuss how the state before the collision can be described in that setup, examine the required fluid-dynamical equations of motion and study the resulting entropy production. While we do here only first steps, we outline a larger program, whicht could lead to a dynamical description of heavy-ion collisions where the only uncertainty lies in the thermodynamic and transport properties of quantum chromodynamics.