The B-Factory was dedicated on October 26th 1998 by the US Energy Secretary Bill Richardson. It has two main parts - the PEP-II storage rings and the BaBar detector.
The 3-km long linear accelerator in Stanford, California uses electromagnetic fields to accelerate electrons and positrons to close to the speed of light:
The B mesons live for about a billionth of a second, in which time they travel less than a millimetre. The BaBar detector observes the particles to which the Bs decay. From the decay products, the physicists can deduce which was the and which was the . They can also measure how far and fast the Bs travel before decaying, and hence they can calculate their lifetimes.
The physicists are interested in the difference in the decay times of the and the . By observing millions of decays, they can build up a distribution of the differences in the decay times. It is predicted that the actual distribution will be different from that which you would get if there were complete symmetry between matter and antimatter.