ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2007, vol. 99, p. -
Measurement of Einstein-Podolsky-Rosen-type flavor entanglement in Υ(4S)→B0B̄0 decays
The neutral B meson pair produced at the Υ(4S) should exhibit a nonlocal correlation of the type discussed by Einstein, Podolsky, and Rosen. We measure this correlation using the time-dependent flavor 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 B̄0 with definite flavor, we find a decoherent fraction of 0.029±0.057, consistent with no decoherence. © 2007 The American Physical Society.