It has long been a puzzle as to why the Universe appears to be predominantly made of matter, whilst anti-matter is relatively rare. The situation presumably has its roots in the formation of the early Universe, and the violation of CP symmetry that allows nature to tell the difference between matter and antimatter. The B meson system is particularly interesting as the effects of symmetry violations are very large (although rates are small). The B meson contains the bottom, or b, quark. To understand the B meson system requires a close synergy between experiment and theory for whilst B mesons can be produced and studied at low energy e+e- colliders, and in great abundance at the Large Hadron Collider as a result of proton collisions, it requires lattice based calculations to provide many of the parameters needed to be able to interpret the results. We are involved in both the current BaBar experiment at SLAC and the future LHCb experiment at CERN studying these issues as well as in the relevant lattice QCD calculations.
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The BaBar experiment studies B mesons made by electron-positron collisions at SLAC. |
Links to the experiments:
