Prediction of intermediate-energy neutron scattering observables from a Dirac optical potential

We construct a global optical potential for intermediate-energy nucleon+208Pb scattering using the Dirac phenomenology. Experimental proton elastic differential cross sections, analyzing powers, spin-rotation functions, total reaction cross sections, and neutron total cross sections are used to construct a Dirac potential spanning an energy range of 95 to 300 MeV. Calculations of n+208Pb scattering observables are performed and significant differences with predictions and measurements of the corresponding proton scattering observables are found. The origins of the differences are explored by performing calculations using a 'gedanken' projectile. The predicted neutron observables are as yet unmeasured and thus have relevance for the newly-constructed intermediate-energy neutron beam facilities. (orig.)