Sensitivity tests on parameters of the nucleon-nucleus dispersive optical model

We have conducted tests of two changes to the formalism of the dispersive optical model (DOM) by making use of a large [Formula Presented] database. One change relaxes the constraint, conventional in DOMs, that the real- and imaginary-volume potentials share the same geometrical parameters. The second change adopts a different functional form for the energy dependence of the surface imaginary potential, which allows its strength to drop off rapidly in the 30–80 MeV region. Radial shapes of the total imaginary potentials for the new DOMs are compared to each other and to those of a microscopic optical model. We also present an improved DOM analysis which models elastic scattering data for [Formula Presented] and [Formula Presented] simultaneously, and which incorporates a newer set of [Formula Presented] total cross-section data.