Factorization of fragment-production cross sections in relativistic heavy-ion collisions

Analysis of the factorizability of several sets of fragment-production cross sections has been performed for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, and ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$ projectiles in the 1 to 2 GeV/nucleon energy region for targets ranging from Be to U. The results of this analysis are considered in terms of geometrical concepts. No evidence is found that there is any dependence of fragmentation channel upon the impact parameter. It is found as well that the projectile dependence of the target factors is much less than that predicted by the abrasion-ablation theory, and also is less than that predicted by an excitation-decay model. Nevertheless, it appears that an excitation and decay mechanism is the dominant process in peripheral fragmentation.