The transverse and longitudinal momentum distributions of projectile fragmentation of unstable nuclei are studied by using a peripheral direct reaction model. We found that the transverse momentum distribution is affected by absorptive cutoff of the fragmentation process, and the width becomes narrower than that of the longitudinal one which remains almost unaffected. The momentum distributions of fragments from unstable projectiles ${}_{}{}^{11}{}_{}{}^{}\mathrm{Be}$ and ${}_{}{}^{11}{}_{}{}^{}\mathrm{Li}$ are studied for various microscopic wave functions. Calculated results with halo wave functions show good agreement with experimental data. We discuss also the difference among various models, the spectator model, Friedman model, and Serber model, for predicting the momentum distribution.

• Received 7 March 1994

DOI:https://doi.org/10.1103/PhysRevC.50.985