Electromagnetic processes in loosely bound nuclei are investigated using an analytical model. In particular, electromagnetic dissociation of ${}^8\mathrm{B}$ is studied and the results of our analytical model are compared to numerical calculations based on a three-body picture of the ${}^8\mathrm{B}$ bound state. The calculation of energy spectra is shown to be strongly model dependent. This is demonstrated by investigating the sensitivity to the rms intercluster distance, the few-body behavior, and the effects of final state interaction. In contrast, the fraction of the energy spectrum which can be attributed to $E1\mathrm{}$ transitions is found to be almost model independent at small relative energies. This finding is of great importance for astrophysical applications as it provides us with a new tool to extract the $E1\mathrm{}$ component from measured energy spectra. An additional, and independent, method is also proposed as it is demonstrated how two sets of experimental data, obtained with different beam energy and/or minimum impact parameter, can be used to extract the $E1\mathrm{}$ component.

• Received 21 January 2003

DOI:https://doi.org/10.1103/PhysRevC.67.045801