Effect of Data Normalization Upon Deuteron Optical-Model Parameters

The sensitivity of optical-model parameters to the absolute normalization of 12-MeV deuteron elastic-scattering angular distributions from ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, and ${}_{}{}^{114}{}_{}{}^{}\mathrm{Cd}$ was studied. Very large variations in parameters were found, particularly when the diffraction pattern of the angular distribution is not pronounced. It is concluded that very accurate absolute normalization of the data may be necessary to make meaningful optical-model analyses. Large parameter fluctuations from element to element, observed in previous deuteron optical-model analyses, are probably due to differences in normalization of the data.