A collider as a quantum computer

TL;DR

This paper reformulates high-energy particle scattering processes as quantum circuits, enabling analysis of entanglement and dynamics using quantum information tools, exemplified by the electron-positron to muon-antimuon process.

Contribution

It introduces a novel circuit-based framework for representing scattering processes, decomposing amplitudes into unitary and non-unitary components for quantum information analysis.

Findings

Scattering matrices can be represented as quantum circuits.

The framework decomposes processes into coherent and postselection effects.

Entanglement structure can be analyzed through circuit dynamics.

Abstract

Scattering processes in high-energy physics are inherently quantum mechanical, yet are typically analyzed at the level of final states, where entanglement appears as a property of the outcome rather than a consequence of the underlying dynamics. We reformulate scattering at the level of the process itself by representing helicity transition matrices as quantum circuits. Once the kinematic configuration and scattering channel are fixed, the problem reduces to a finite-dimensional quantum map, making a circuit description natural. Within this framework, an example of the process $e^+e^-\to \mu^+\mu^-$ is shown, which decomposes into unitary and non-unitary components, corresponding to coherent mixing and postselection effects. This representation reorganizes the amplitude into distinct operational elements, providing a perspective in which collider processes can be viewed as constrained quantum circuits and their entanglement structure can be understood in terms of the underlying circuit dynamics, opening the door to analyzing their properties using the language of quantum information.