New effective interactions for hypernuclei in density dependent relativistic mean field model

TL;DR

This paper introduces new effective $\Lambda N$ interactions within a density dependent relativistic mean field model, fitted to hypernuclei data, and explores their implications for hypernuclear matter and neutron stars.

Contribution

The paper proposes six new effective interactions for hypernuclei based on fitting to experimental data, enhancing the modeling of hypernuclear systems within the relativistic mean field framework.

Findings

The ratios $R_\sigma$ and $R_\omega$ are strongly correlated with a linear relation.

The new interactions accurately reproduce $\Lambda$ separation energies.

These interactions impact the equation of state of hypernuclear matter and neutron star properties.

Abstract

New effective $\Lambda N$ interactions are proposed for the density dependent relativistic mean field model. The multidimensionally constrained relativistic mean field model is used to calculate ground state properties of eleven known $\Lambda$ hypernuclei with $A\ge 12$ and the corresponding core nuclei. Based on effective $NN$ interactions DD-ME2 and PKDD, the ratios $R_\sigma$ and $R_\omega$ of scalar and vector coupling constants between $\Lambda N$ and $NN$ interactions are determined by fitting calculated $\Lambda$ separation energies to experimental values. We propose six new effective interactions for $\Lambda$ hypernuclei: DD-ME2-Y1, DD-ME2-Y2, DD-ME2-Y3, PKDD-Y1, PKDD-Y2 and PKDD-Y3 with three ways of grouping and including these eleven hypernuclei in the fitting. It is found that the two ratios $R_\sigma$ and $R_\omega$ are correlated well and there holds a good linear relation between them. The statistical errors of the ratio parameters in these effective interactions are analyzed. These new effective interactions are used to study the equation of state of hypernuclear matter and neutron star properties with hyperons.