Scattering of mesons in quantum simulators

TL;DR

This paper demonstrates how current quantum simulators can emulate meson scattering in low-dimensional gauge theories, providing a new way to study real-time dynamics of fundamental particle interactions.

Contribution

It introduces protocols for simulating meson collisions in a $(1+1)$-dimensional $ ext{Z}_2$ lattice gauge theory using Rydberg-atom arrays, including theoretical benchmarks and numerical simulations.

Findings

Quantum simulators can measure meson scattering amplitudes.

Inelastic scattering channels with new meson production are observable.

Numerical simulations match theoretical cross section predictions.

Abstract

Simulating real-time evolution in theories of fundamental interactions represents one of the central challenges in contemporary theoretical physics. Cold-atom platforms stand as promising candidates to realize quantum simulations of non-perturbative phenomena in gauge theories, such as vacuum decay and hadron collisions, in prohibitive conditions for direct experiments. In this work, we demonstrate that present-day quantum simulators can imitate linear particle accelerators, giving access to S-matrix measurements of elastic and inelastic meson collisions in low-dimensional Abelian gauge theories. Considering for definiteness a $(1+1)$-dimensional $\mathbb{Z}_2$-lattice gauge theory realizable with Rydberg-atom arrays, we present protocols to observe and measure selected meson-meson scattering processes. We provide a benchmark theoretical study of scattering amplitudes in the regime of large fermion mass, including an exact solution valid for arbitrary coupling strength. This allows us to discuss the occurrence of inelastic scattering channels, featuring the production of new mesons with different internal structures. We present numerical simulations of realistic wavepacket collisions, which reproduce the predicted cross section peaks. This work highlights the potential of quantum simulations to give unprecedented access to real-time scattering dynamics.