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Measurement of EPR-type flavour entanglement in Upsilon(4S)->B0 B0bar decays

A. Go·A. Bay
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Abstract

The neutral B-meson pair produced at the Upsilon(4S) should exhibit a non-local correlation of the type discussed by Einstein, Podolski, and Rosen (EPR). We measure this correlation using the time-dependent flavour asymmetry of semileptonic B0 decays, which we compare with predictions from quantum mechanics and two local realistic models. The data are consistent with quantum mechanics, and inconsistent with the other models. Assuming that some B pairs disentangle to produce B0 and B0bar with definite flavour, we find a decoherent fraction of 0.029+-057, consistent with no decoherence.

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A. Go, A. Bay. 2007-02-28. Measurement of EPR-type flavour entanglement in Upsilon(4S)->B0 B0bar decays. https://doi.org/10.1103/physrevlett.99.131802

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