New directions in elementary particle physics: p$\overline{p}$ from very low to very high energies

The recent development of cooling techniques offers the possibility of obtaining 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 pp 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 pp interactions can give information on the unification of weak and electromagnetic interactions, and on QCD. (47 refs)