Das hochbesetzte Quark-Gluon-Plasma auf dem Gitter

• Antragsteller: Professor Dr. Jürgen Berges
• Fachliche Zuordnung: Kern- und Elementarteilchenphysik, Quantenmechanik, Relativitätstheorie, Felder
• Förderung: Förderung von 2013 bis 2017
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 233033195

Understanding the real-time dynamics of non-abelian plasmas is one of the most pressing issues in the physics of relativistic heavy-ion collisions and of great relevance for the physics of the early universe. Since basic properties of the far-from-equilibrium dynamics are non-perturbative, a quantitative understanding from first principles requires simulations using lattice gauge theory. It is a major development of recent years that important aspects of the non-equilibrium quantum dynamics can be formulated in terms of classical-statistical lattice gauge theory, which can be simulated in real time. This includes important phenomena such as plasma instabilities, turbulence or even possible Bose condensation far from equilibrium. A quantitative description requires simulations in lattice gauge theory with dynamical fermions in real time. These are computationally feasable taking into account algorithmic developments employing 'low-cost fermions'. Based on our recent successful computations in non-equilibrium pure gauge theory and in Yukawa-type theories with Wilson fermions, this proposal aims at performing these calculations for quantum chromodynamics (QCD). For the first time, important phenomena such as quark production including the non-linear backreaction will be described. Most strikingly, this will allow us to study non-equilibrium dynamics at non-zero baryon number density without encountering a 'sign' or 'overlap' problem. In particular, we will confront the lattice simulation results with the different analytical proposals of how thermalization could proceed in the idealized limit of a collision with very large nuclei at high energy. For the longitudinally expanding system, that development will be as close as one can get with present-day technology towards a description of the early-time dynamics of a heavy-ion collision from first principles.

• DFG-Verfahren: Sachbeihilfen