Four-Particle Dalitz Plots to Visualize Atomic Break-Up Processes

We introduce a new method to analyze four-body fragmentation processes, which is basically an extension of Dalitz plots commonly used in particle physics to analyze three-body fragmentation processes. It enables for the first time to present multiple differential cross sections as a function of all four fragments without loss of any part of the total cross section in the integral spectrum. As a first example, the technique is applied to ionization processes in atomic collisions.