Relativistic nucleon optical potentials with isospin dependence in Dirac Brueckner Hartree-Fock approach

TL;DR

This paper develops a relativistic optical model potential for nucleon-nucleus scattering using the Dirac-Brueckner-Hartree-Fock approach with isospin dependence, and compares the results with experimental data and phenomenological models.

Contribution

It introduces a microscopic, isospin-dependent relativistic optical potential based on DBHF calculations with an improved local density approximation.

Findings

Good agreement with experimental scattering data across energies

Inclusion of isospin dependence improves model accuracy

Constant range parameter suffices for finite-range correction

Abstract

The relativistic optical model potential (OMP) for nucleon-nucleus scattering is investigated in the framework of Dirac-Brueckner-Hartree-Fock (DBHF) approach using the Bonn-B One-Boson- Exchange potential for the bare nucleon-nucleon interaction. Both real and imaginary parts of isospin-dependent nucleon self-energies in nuclear medium are derived from the DBHF approach based on the projection techniques within the subtracted T -matrix representation. The Dirac potentials as well as the corresponding Schrodinger equivalent potentials are evaluated. An improved local density approximation is employed in this analysis, where a range parameter is included to account for a finite-range correction of the nucleon-nucleon interaction. As an example the total cross sections, differential elastic scattering cross sections, analyzing powers for n, p + 27Al at incident energy 100 keV < E < 250 MeV are calculated. The results derived from this microscopic approach of the OMP are compared to the experimental data, as well as the results obtained with a phenomenological OMP. A good agreement between the theoretical results and the measurements can be achieved for all incident energies using a constant value for the range parameter.