B factories are particle colliders at which specific subatomic particles – B mesons – are being abundantly produced. The purpose of these factories is to study the properties of the decay of the particles in great detail, in order to shed light on a mystery of eminently larger scale: why do we live in a universe composed of matter and no anti-matter? In expert language, the asymmetry between matter and anti-matter is called the CP asymmetry. It represents a necessary condition for our universe to evolve in the way it has, with its visible part being composed almost completely of particles and no anti-particles. There is an unanswered puzzle, though: the amount of the asymmetry as measured at the subatomic level is much too small to successfully explain the matter asymmetry of the universe.

This book is an introductory text to physics laws of the CP asymmetry, touching on experimental requirements needed to perform such measurements at the subatomic level, and illustrating the main findings of the contemporary B factories. Deviations between the experimental results and predictions based on the current theoretical knowledge are exposed and discussed in terms of the near-future frontier particle physics experimental endeavours.