Towards Quantum Simulation of Meson Scattering in a Z2 Lattice Gauge Theory

Abstract: Scattering processes are fundamental for understanding the structure of matter. At the same time, simulating the real-time dynamics of scattering processes on classical computers is challenging. Quantum computing offers a promising avenue for efficiently simulating such phenomena. In this work, we investigate meson scattering in a (1+1)-dimensional Z2 lattice gauge theory with staggered fermions. We construct mesonic wave packets using a quantum subspace expansion (QSE) approach to obtain high-fidelity meson creation operators. Using these, we propose an efficient quantum circuit decomposition for meson wave packet preparation using Givens rotations. Our approach significantly reduces the circuit depth compared to previous methods. Simulating the time evolution of wave packets classically with Tensor Networks, we observed both elastic and inelastic scattering and provide a detailed analysis of energy transfer, entanglement entropy, and particle production. Our results demonstrate the feasibility of simulating inelastic meson scattering on near-term quantum devices and provide insights into meson dynamics in confining gauge theories.