Rows on rows - a theory for collisions between heavy ions at high energy

The double differential cross section dsigma/dΩdE is computed for protons and pions from collisions between nuclei at high energies (250 to 2100 MeV/nucleon). The following is derived within Glauber theory: At high energies the interaction between two nuclei reduces to a series of collisions between rows of target nucleons and rows of projectile nucleons. The scattering 'rows on rows' can be obtained from a one-dimensional cascade calculation. It is performed in a simple approximation, using experimental nucleon-nucleon cross sections as the only input. The introduction of the Δ-degree of freedom leads to a satisfactory description of the proton and pion data at 2.1 GeV/nucleon. At 250 MeV/nucleon the agreement with experiment compares favourably with the one achieved in other approaches. A scaling law may be the reason why many simple approaches come already close to experiment. The question of thermalization is discussed. (Auth.)