Longitudinal momentum distributions and total diffraction and stripping cross sections for production of ${}^{10}\mathrm{Be}$ and ${}^{14}\mathrm{C}$ fragments in ground and excited states, by removal of a valence neutron or a core neutron, are studied in the eikonal approximation for the ${}^9\mathrm{Be}{(}^{11}\mathrm{Be},$ ${}^{10}\mathrm{Be}+\gamma )$ and ${}^9\mathrm{Be}{(}^{15}\mathrm{C},$ ${}^{14}\mathrm{C}+\gamma )$ reactions. A consistent description of recent exclusive data for individual ${}^{10}\mathrm{Be}$ states is obtained, giving support to the procedure. Predictions for ${}^{14}\mathrm{C}$ are in agreement with available inclusive and limited inclusive data, and argue for halo model for ${}^{15}\mathrm{C}.$ The sensitivity of the results to the structural assumptions and interaction potentials is discussed.

• Received 8 June 2000

DOI:https://doi.org/10.1103/PhysRevC.62.044602