The route to ultra-low energy antihydrogen

We begin by discussing the concept and field of antimatter and how quantum mechanics and relativity led to its discovery. We describe how neutral antimatter, in the form of antihydrogen, is a natural test bed for tests of CPT and the weak equivalence principle. We go on to describe how cold antihydrogen can be formed by creating, trapping, cooling, and combining antiprotons and positrons at a facility such as the antiproton decelerator at CERN. We finish by describing the recent success in producing low-energy antihydrogen and how future developments are geared toward achieving the above tests and beyond. (C) 2004 Elsevier B.V. All rights reserved.