Which Potentials have to be Surface Peaked to Reproduce Large Angle Proton Scattering at High Energy?

Abstract

Corrections to the usual form factors of the optical potential are studied with a view to getting a better fit for proton elastic scattering at large angles on 40Ca at 497 and 800 MeV. When a real surface form factor is added to the central potential in the Schrbdinger formalism, the experimental data are as well reproduced as in the standard Dirac formalism. Coupling to the strong 3- collective state gives a better fit. The use of surface corrections to the imaginary Dirac potential also gives improved results. A slightly better fit is obtained by coupling to the 3- state with, at the same time, a weakening of these corrections. Further corrections to the potential do not give significant improvements.