DIFFERENCES IN OPTICAL MODEL PARAMETERS BETWEEN PAIRS OF ISOTOPES AS FOUND FROM DIFFERENCE FUNCTIONS OF SCATTERING DATA

The relative differences in differential cross sections, and differences in polarization, for pairs of isotopes are fitted to theoretical values of these functions computed from the optical model, for elastic scattering of protons between 12 and 50 MeV. The method eliminates errors in normalization common to the two isotopes, and detects errors in relative normalization and data points of low relative accuracy. Although some trends are found for 58, 60Ni as a function of energy, most of the present data are either insufficiently accurate or not available at enough energies to allow firm conclusions to be drawn about shifts in parameters and their relation to the symmetry term in the potential, and to nuclear structure effects. © 1969.