Influence of the symmetry energy on the nuclear binding energies and the neutron drip line position

Abstract

A clear connection can be established between properties of nuclear matter and finite-nuclei observables, such as the correlation between the slope of the symmetry energy and the dipole polarizability, or between compressibility and the isoscalar monopole giant resonance excitation energy. Establishing a connection between realistic atomic nuclei and an idealized infinite nuclear matter leads to a better understanding of underlying physical mechanisms that govern nuclear dynamics. In this work, we aim to study the dependence of the binding energies and related quantities (e.g., location of drip lines, the total number of bound even-even nuclei) on the symmetry energy ${S}_{2}(\ensuremath{\rho})$. The properties of finite nuclei are calculated by employing the relativistic Hartree-Bogoliubov model, assuming even-even axial and reflection symmetric nuclei. Calculations are performed by employing two families of relativistic energy density functionals, based on different effective Lagrangians, constrained to a specific symmetry energy at the saturation density $J$ within the interval of 30--36 MeV. Nuclear binding energies and related quantities of bound nuclei are calculated between $8\ensuremath{\le}Z\ensuremath{\le}104$ from the two-proton to the two-neutron drip line. As the neutron drip line is approached, the interactions with stiffer $J$ tend to predict more bound nuclei, resulting in a systematic shift of the two-neutron drip line towards more neutron-rich nuclei. Consequentially, a correlation between the number of bound nuclei ${N}_{\mathrm{nucl}}$ and ${S}_{2}(\ensuremath{\rho})$ is established for a set of functionals constrained using the similar optimization procedures. The direction of the relationship between the number of bound nuclei and the symmetry energy highly depends on the density under consideration.

Topics & Concepts