New directions in elementary particle physics - p anti-p from very low to very high energies

The recent development of cooling techniques offers the possibility to obtain intense sources of antiprotons, stacking them as they are produced at a multi-GeV accelerator. The wide array of applications presently considered, ranging from reactions at extremely low energy in the case of p anti p atoms to reactions at hundreds of GeV in the case of head-on collisions between protons and antiprotons accelerated at the same time in a super synchrotron, is reviewed. Special emphasis is put on the present CERN program, which will reach the data-taking stage in 1981. The study of p anti p interactions is meant as an illustration of how new possibilities open new directions in elementary particle physics, whether reaching energies hitherto much beyond accelerator possibilities or developing new lower-energy beams improved tremendously over those presently available.