A study of Lambda hypernuclei within the Skyrme-Hartree-Fock Model

TL;DR

This paper models Lambda hypernuclei using the Skyrme-Hartree-Fock approach, fitting parameters to experimental data, and explores their properties across a wide mass range, also examining implications for neutron stars.

Contribution

It introduces new parameter sets for Lambda-nucleon interactions fitted to extensive hypernuclear data and analyzes their impact on hypernuclear and neutron star properties.

Findings

Lambda binding energies are sensitive to the choice of parameter sets.

Lambda orbit radii and effective masses depend on the fitted parameters.

Hypernuclear stability varies with baryon number and influences neutron star models.

Abstract

We investigate the properties of the single Lambda hypernuclei within a Skyrme-Hartree-Fock (SHF) model. The parameters of the Skyrme type effective lambda-nucleon (Lambda N) interaction are obtained by fitting to the experimental Lambda binding energies of hypernuclei with masses spanning a wide range of the periodic table. Alternative parameter sets are also obtained by omitting nuclei below mass number 16 from the fitting procedure. The SHF calculations are performed for the binding energies of the Lambda single-particle states over a full mass range using the best fit parameter sets obtained in these fitting procedures and the results are compared with the available experimental data. The data show some sensitivity to the parameter sets obtained with or without including the nuclei below mass 16. The radii of the Lambda orbits in the hypernuclear ground states and the Lambda effective mass in nuclear matter show some dependence on different parameter sets. We present results for the total binding energy per baryon of the hypernuclei over a large mass region to elucidate their stability as a function of the baryon number. We have also employed the our best fit Lambda N parameter sets to investigate the role of hyperons in some key properties of neutron stars.