Data for the fragmentation of high energy gold projectiles were recently analyzed by Dreute et al. with the assumption that the average A/Z ratio of the residues was equal to that of the projectile. The momenta of the projectile fragments from this analysis were dramatically larger than expected. We point out that the assumption of a constant A/Z is inconsistent with a large body of data and leads to an overestimation of both the fragment mass and the momentum distribution. A better description of the variation of the residue A/Z ratio can be found in the prescription developed by Sümmerer et al. based on a broad range of data.

• Received 24 April 1992

DOI:https://doi.org/10.1103/PhysRevC.47.413