RELATIVISTIC OPTICAL MODEL FOR PROTON-NUCLEUS ELASTIC SCATTERING

The relativistic description of the proton-nucleus elastic scattering can be considered within the framework of a relativistic optical potential model. The elastic scattering of proton with the nuclei 12 C , 16 O , 20 Ne , and 24 Mg at 800 MeV and 1.04 GeV are studied for relativistic and nonrelativistic treatments. The real optical potentials and the differential cross sections of these reactions are calculated. The obtained results are compared with the corresponding results obtained from the calculation depending on the Woods–Saxon optical potential which were adjusted to fit the experimental data. The present results are in good agreement with the experimental data.

Positron Impact Ionisation of H and He Atoms: The Continuum Model

The continuum optical potential model is used to calculate the ionisation cross sections of H and He by positron impact. The present e+-H result is compared with the recent first measurement of e+ -H ionisation cross sections. The e+ -He calculation is also presented, together with the experimental measurements. A comparison with other theoretical results is also given.