The widths of the longitudinal momentum distributions of projectilelike fragments produced in ${(}^{11}$Be${,}^{10}$Be+n) and in ${(}^8$B${,}^7$Be+p) breakup reactions are analyzed using a single-particle description. The strong absorption limit of the Serber model reproduces both data sets quite accurately. The transparent limit, on the other hand, can reproduce the width of the ${}_{}{}^{11}{}_{}{}^{}\mathrm{Be}$ data reasonably well but it fails dramatically for the ${}_{}{}^8{}_{}{}^{}\mathrm{B}$ data. The reason is that the absorption of the projectilelike fragment has a much larger effect on the width when the orbital angular momentum of the valence nucleon is nonzero. © 1996 The American Physical Society.

• Received 29 November 1995

DOI:https://doi.org/10.1103/PhysRevC.53.2007