Theoretical study of elastic electron scattering off stable and exotic nuclei

TL;DR

This paper compares theoretical predictions of elastic electron scattering off stable and exotic nuclei using Skyrme and covariant models, with implications for future experiments on neutron-rich isotopes.

Contribution

It introduces a comprehensive theoretical survey of electron scattering on exotic nuclei using mean field charge densities and Helm model fits, aiding future experimental analysis.

Findings

Charge densities fitted with Helm models reveal neutron-number effects.

Correlations among scattering observables are identified across isotopic chains.

Theoretical predictions align well with existing data for stable isotopes.

Abstract

Results for elastic electron scattering by nuclei, calculated with charge densities of Skyrme forces and covariant effective Lagrangians that accurately describe nuclear ground states, are compared against experiment in stable isotopes. Dirac partial-wave calculations are performed with an adapted version of the ELSEPA package. Motivated by the fact that studies of electron scattering off exotic nuclei are intended in future facilities in the commissioned GSI and RIKEN upgrades, we survey the theoretical predictions from neutron-deficient to neutron-rich isotopes in the tin and calcium isotopic chains. The charge densities of a covariant interaction that describes the low-energy electromagnetic structure of the nucleon within the Lagrangian of the theory are used to this end. The study is restricted to medium and heavy mass nuclei because the charge densities are computed in mean field approach. Since the experimental analysis of scattering data commonly involves parameterized charge densities, as a surrogate exercise for the yet unexplored exotic nuclei, we fit our calculated mean field densities with Helm model distributions. This procedure turns out to be helpful to study the neutron-number variation of the scattering observables and allows us to identify correlations of potential interest among some of these observables within the isotopic chains.