Entanglement, Bell Inequalities and Decoherence in Particle Physics

Abstract

We demonstrate the relevance of entanglement, Bell inequalities and decoherence in particle physics. In particular, we study in detail the features of the "strange" K 0K 0 system as an example of entangled meson-antimeson systems. The analogies and differences to entangled spin-1 2 or photon systems are worked out, the effects of a unitary time evolution of the meson system is demonstrated explicitly. After an introduction we present several types of Bell inequalities and show a remarkable connection to CP violation. We investigate the stability of entangled quantum systems pursuing the question of how possible decoherence might arise due to the interaction of the system with its "environment". The decoherence is strikingly connected to the entanglement loss of common entanglement measures. Finally, some outlook of the field is presented.

Measurement of Einstein-Podolsky-Rosen-Type Flavor Entanglement inΥ(4S)→B0B¯0Decays

“…Many experiments have since been performed and found excellent agreement with the prediction of QM (although no "loophole"-free Bell test has yet been performed) [3]. Most of these studies have used pairs of optical photons; it is also interesting to test EPR correlations in massive systems [4] at much higher energies [5]. In this Letter, we present a study of EPR correlation in the flavour of B-meson pairs produced at the Υ(4S).…”

Bell’s Universe: A Personal Recollection

“…, where the short-lived kaon K S and the long-lived kaon K L played the role of spin up ⇑ and spin down ⇓ , we found for the like-strangeness probability [187] (see also reviews [188,189])…”

Testing EPR locality using B-mesons

“…2 (see, e.g., [17]). The correlation (2.5) in QM violates the Bell inequality, provided that there exists an LRT describing the meson system in which the decay times (t l , t r ) play a similar role as the angle parameters in the usual photon polarization experiment.…”