Quantum pions

TL;DR

This paper demonstrates that neutral kaon decay-produced pion states exhibit quantum entanglement, contextuality, and Bell nonlocality in isospin space, offering a novel multipartite Bell test with qutrits.

Contribution

It reinterprets experimental isospin amplitudes to quantify entanglement and nonlocality in pion states, providing a new perspective on quantum correlations in particle physics.

Findings

Pion states are shown to be entangled and nonlocal in isospin space.

Experimental data can be used to quantify the degree of quantum correlations.

The three-pion state enables a genuine multipartite Bell test with qutrits.

Abstract

We show that two- and three-pion states produced in the decay of neutral kaons are contextual, entangled, and Bell nonlocal in isospin space. By reinterpreting the experimental values of the different isospin amplitudes, we can determine the amount of entanglement enjoyed by these states and the extent to which they violate the non-contextuality and Bell locality inequalities. Notably, the three-pion state offers a genuine multipartite test of Bell nonlocality with qutrits.