Real-time simulation of jet energy loss and entropy production in high-energy scattering with matter

Abstract Real-time scattering dynamics in gauge theories are central to high-energy nuclear physics, but they are notoriously hard to access from first principles. In particular, it remains unclear how a simple propagating probe becomes modified and quantum-mechanically mixed with a dense, dynamical target during a collision. In analogy to high-energy nuclear scattering experiments, we study a real-time scattering process between a propagating state and a dense target in 1 + 1-d massive QED. In our setup, we identify three distinct regimes that qualitatively characterize the evolution: for a dilute medium, the incoming probe state evolves nearly ballistically; in an intermediate setting, it traverses the matter, locally exciting it; and for dense targets, one approaches a black-disk limit, where the matter acts as a strong wall potential. Here we show evidence that the probe’s energy loss rate scales linearly with the path length in the medium, and we study how the entanglement entropy reveals the mixing between the probe and medium states. With the goal of one day replicating high-energy nuclear experiments in quantum devices, we briefly discuss how the current tensor network-based simulations can be translated to a quantum simulator.