Revealing Bell's Nonlocality for Unstable Systems in High Energy Physics

TL;DR

This paper proposes a Bell inequality test for unstable meson-antimeson systems in high energy physics, enabling direct experimental verification of quantum nonlocality in these decaying systems using current accelerator technology.

Contribution

It introduces a Bell inequality tailored for unstable systems, facilitating the first direct experimental test of nonlocality in high energy physics meson systems.

Findings

Bell inequality applicable to decaying systems

Feasibility of experimental test at accelerator facilities

Exploration of entanglement and CP violation in meson systems

Abstract

Entanglement and its consequences - in particular the violation of Bell inequalities, which defies our concepts of realism and locality - have been proven to play key roles in Nature by many experiments for various quantum systems. Entanglement can also be found in systems not consisting of ordinary matter and light, i.e. in massive meson--antimeson systems. Bell inequalities have been discussed for these systems, but up to date no direct experimental test to conclusively exclude local realism was found. This mainly stems from the fact that one only has access to a restricted class of observables and that these systems are also decaying. In this Letter we put forward a Bell inequality for unstable systems which can be tested at accelerator facilities with current technology. Herewith, the long awaited proof that such systems at different energy scales can reveal the sophisticated "dynamical" nonlocal feature of Nature in a direct experiment gets feasible. Moreover, the role of entanglement and CP violation, an asymmetry between matter and antimatter, is explored, a special feature offered only by these meson-antimeson systems.