Work

Quantum-entangled pions

Year: 2025

Type: article

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 noncontextuality and Bell locality inequalities. Notably, the two-pion case provides an example of a state that is more Bell nonlocal, as witnessed by the Collins-Gisin-Linden-Massar-Popescu inequality, than the maximally entangled one. The three-pion state offers a genuine multipartite test of Bell nonlocality with qutrits. This is the first instance where quantum properties like entanglement and contextuality are demonstrated to exist within the internal space of isospin.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/2yst-qkcv

Authors: M. Fabbrichesi, R. Floreanini, E. Gabrielli, L. Marzola

Institutions: Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, University of Trieste, National Institute of Chemical Physics and Biophysics, University of Tartu

Language: English

Topic: Quantum Mechanics and Applications

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funder: Eesti Teadusagentuur

Awards: CERN Science Consortium of Estonia, Towards a joint solution to distinct theoretical puzzles: the axion-flavor connection, G4473005422