Monday, April 23, 2007

Physics stories of the last 3 months

Here are the links to some of the great happenings in the elementary particle physics world, with a few comments in my own words.

Here is the link to the story on the mixing of neutral D mesons. This was already observed a long time ago in the K and B meson systems. Mesons are particles with one quark and anti-quark. Quarks come in 6 flavours: up, down, strange, charm, b and top, given in order of increasing mass. K mesons have strange and a light quark, D mesons have a strange and a light quark, B have a b and a light quark. The effect is highly suppressed in the D meson systems and the BELLE experiment at KEK in Japan had a huge number of D mesons that they used to find the effect.

It is the BELLE experiment which also saw quantum entanglement in B-mesons. It is reported here in this preprint. The idea of entanglement was first given by Einstein, Rosen and Podolsky. I don't know much more about this.

The other great story is the result from the MiniBoone experiment. The AIP press release is entitled ``One Neutrino Anomaly is Resolved.'' Neutrino oscillations have been established beyond doubt in the last decade, first by the Sudbury Neutrino Observatory and by the Super Kamiokande experiment in Japan. There were contradictory experimental findings from a Los Alamos Experiment which now seem to have been repudiated by the MiniBoone experiment.

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