antimatter - every matter particle has an antimatter partner, a particle that has exactly the same mass and exactly opposite electric charge.  The existence of antimatter partners is required by the laws of modern physics.  If a particle comes into contact with its own antiparticle, the pair can annihilate and produce pure energy.  Conversely, from this pure energy can come other particle-antiparticle pairs.
B factory - the term used to describe any of several accelerator facilities and detectors that aim to produce sufficient B mesons to study CP violation.
beam current - a measure of the number of particles per unit time passing a point in the trajectory.
CP symmetry - see page 2a in FAQ.
hadron - any observable particle that is affected by the strong force.
lepton - an elementary particle that is not affected by the strong force.
luminosity - a measure of collision rate between intended colliding particles.
meson - a hadron that is composed of a quark (any flavor) and an antiquark (any flavor).
quark - an elementary particle that is affected by the strong force.  All hadrons contain quarks.
storage ring - A device designed to hold a beam in a closed orbit at constant energy for as long as possible.
weak interaction - one of the four forces of physics, and the only one that exhibits CP violation.