Mesons violate Bell’s inequality
6 November 2003
The famous Bell's inequality of quantum mechanics has been tested in a high-energy particle physics experiment for the first time. The inequality was violated by three standard deviations in experiments with B mesons at the KEK laboratory in Japan - yet again confirming the predictions of quantum theory (arxiv.org/abs/quant-ph/0310192; J. Mod. Optics to be published). Previously most Bell's inequality experiments have been performed with photons or ions.
It's interesting to say the least, though of course it's not yet been reproduced. opinions? wild speculation?