Effects of nonlocal potentials on(p,d)transfer reactions

Abstract

Background: Although local phenomenological optical potentials have been standardly used to interpret nuclear reactions, recent studies suggest the effects of non-locality should not be neglected. Purpose: In this work we investigate the effects of non-locality in (p, d) transfer reactions using non-local optical potentials. We compare results obtained with the dispersive optical model to those obtained using the Perey-Buck interaction. Method: We solved the scattering and bound-state equations for the non-local version of the dispersive optical model. Then, using the distorted wave Born approximation, we calculate the transfer cross section for (p, d) on 40 Ca at Ep=20, 35 and 50 MeV. Results: The inclusion of non-locality in the bound state has a larger effect than on the scattering states. The overall effect on the transfer cross section is very significant. We found an increase due to non-locality in the transfer cross section of ≈ 30 − 50% when using the Perey-Buck interaction and ≈ 15 − 50% when using the dispersive optical potential. Conclusions: Although the details of the non-local interaction can change the magnitude of the effects, our study shows that qualitatively the results obtained using the dispersive optical potential and the Perey-Buck interaction are consistent, in both cases the transfer cross sections are significantly increased.

Asymmetry dependence of Gogny-based optical potential

“…NSM has been applied to neutron and proton scattering off 40−48 Ca using Gogny D1S interaction. We focus on incident energies below 40 MeV where NSM has demonstrated to be efficient [9,15]. Results are summarized in Figs.…”

“…The nice agreement with reaction observables provided by NSM is mainly due to the correct description of the targetnucleus radius and the good description of collective states of the target nucleus provided by the Random-Phase Approximation (RPA) for doubly-closed shell nuclei. In this work, we apply NSM to nucleon scattering off both 40 Ca and 48 Ca in order to study optical potential dependence on the isospin asymmetry of the target-nucleus. In Sec.…”

“…In previous attempts [9,15], Nuclear Structure Method (NSM) [7] has been successfully applied to describe nucleon scattering off 40 Ca using Gogny D1S interaction as sole input. This method is based on Green's function formalism.…”

“…An analysis of neutron and proton scattering off 40,48 Ca has been carried out. Real and imaginary potentials have been generated using the Nuclear Structure Method for scattering with the Gogny D1S nucleon-nucleon effective interaction.…”

Non local microscopic potentials for calculation of scattering observables of nucleons on deformed nuclei

“…Microscopic approches are being developped in order to improve prediction power and solve the aformentionned issue [1]. Potentials obtained microscopically are non local, and recent studies [2][3][4] have emphasized the importance of treating explicitely this nonlocality, and not through a localization procedure. These developments lead to the need of a computation code capable of solving coupled channel equations with non local potentials.…”