Peter Dortmans

Structure of Light Mass (Exotic) Nuclei as Evidenced by Scattering from Hydrogen

Microscopic optical model potentials generated by full folding of realistic two-nucleon (NN) interactions with nuclear structure specified by large basis shell model calculations have been constructed. With those (nonlocal) potentials, predictions of light mass nuclei-hydrogen scattering result that agree well with observations of cross sections and analyzing powers.

pp ↔ π + d process at low energy: Interplay between s - and p -wave mechanisms

The large variety of experimental data around the pion-production threshold are compared with a meson-exchange isobar model which includes the pion-nucleon interaction in s-- and p-waves. Theoretical results obtained with two different NN potentials (Bonn and Paris) indicate that the behavior of the excitation function at threshold is sensitive to the details of the NN correlations. The complete model presented, while developed originally to reproduce the reaction around the Delta resonance, is shown to describe well the integral (Coulomb-corrected) cross-section at threshold along with its angular distribution. At low energies the angular dependence of the analyzing power Ay0 is well reproduced also. Finally, the energy dependence of the analyzing power for theta=90 from threshold up to the Delta resonance is considered and discussed.