BaBar - a new detector to study CP violation in the B system

To explain why the Universe is dominated by matter and has so little antimatter needs a mechanism which distinguishes matter from antimatter. This is accomplished, together with a few other conditions, by introducing the non-conservation of CP symmetry in the theory describing the interactions between the particles at the early stage of the universe. CP violation - the subtle disregard of physics for a combined particle/ antiparticle and mirror reflection symmetry - was first observed in kaon decays 30 years ago by J.H. Christenson, J.W. Cronin, V.L. Fitch and R. Turlay but has defied a unique and fundamental explanation ever since. However at the turn of the century we should begin to understand its origin as the next generation of kaon decay experiments at CERN and Fermilab on the one hand and new detectors at the Fermilab Tevatron, at DESY's HERA collider and as B programmes at Cornell (December 1993, page 22, KEK in Japan (April 1994, page 18) and SLAC, Stanford (PEPII - March 1994, page 10) on the other hand produce their first data. These new detectors will open up the study of CP-violation in another system - B mesons containing the fifth ('b') quark, where the CPviolation effects are expected to be larger