Abstract
A feature universally employed in the application of the Glauber approximation to the scattering of a projectile by a many-particle target is the assumption that the complex phase shift itself carries a phase which is independent of the impact parameter . The most common assumption is that , where is real and is the real-to-imaginary ratio of the forward amplitude for elastic scattering of the projectile (or one of its constituents) on the constituents of the target. Since is proportional to an eikonal integral through an effective potential , this form also assumes that , i.e., that the real and imaginary parts of this potential have the same radial shapes. In recent years this approximation has been applied to heavy-ion elastic scattering in the relatively low-energy range below MeV/nucleon. Phenomenological optical potentials for these same nuclei and energies strongly violate the above condition, although they do approximate it in the surface region responsible for scattering to angles dominated by Fraunhofer oscillations. The Glauber approximation provides a qualitative fit to these oscillations, indicating that it is at least employing the correct nuclear radii. However, it grossly overestimates the absorption at larger angles in cases where these angles are sensitive to the interior of the potential. This failure may provide a sensitive means of assessing the effects of Pauli blocking on in-medium scattering.
- Received 22 April 1996
DOI:https://doi.org/10.1103/PhysRevC.55.1353
©1997 American Physical Society