Soft hadronic interactions at the CERN colliders

Our experimental knowledge of low transverse momentum strong interactions has been considerably improved by the recent few years of operation of the CERN anti-p complex. The (long awaited) comparison of anti-pp and pp collisions has been possible at the ISR (31-63 GeV), while the Santi-ppS Collider has provided a first global picture in a new energy regime (540 GeV). Low transverse momentum strong interactions make up more than 99% of hadronic cross sections (often referred to as ''minimum bias'' physics, or ''log s'' physics for its weak logarithmic dependence on the c.m. energy Esub(CM) = √s) and have been studied by several generations of accelerators. The understanding of the geneal phenomena of hadronization and of diffractive (coherent) processes, in particular, is believed to be an essential ingredient of a field theory of multiparticle production and confinement. Only models, however, have been so far available as a guidance. Significant theoretical advances are needed in this difficult area, to escape the conclusion that the phenomena involved may be intrinsically too complicated for any basic explanation. 22 figs.; 70 refs.