Cold breakup of spectator residues in nucleus-nucleus collisions at high energy

Inclusive data from fragmentation reactions of the type AP+AT→Z+X are analyzed and a reaction mechanism is proposed. A projectile AP (p, He, α, or Ne) collides with a target nucleus AT (Au) and one fragment with charge Z and energy E is observed at a solid angle Ω. Projectile energies vary between $84A$ MeV and several A GeV. We propose a parametrization for the triple differential cross section d³σdΩdEdZ with six free parameters. The parametrization generalizes the two-vector model which is often used to describe spallation products in proton-nucleus collisions. By fitting data from various experiments we establish a systematics of the six parameters. The experimental values of the parameters can be quantitatively understood in a model where the target nucleus breaks into several fragments similar to the shattering of glass.