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

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 >= 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 A separation energies to experimental values. We propose six new effective interactions for A 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 correlate well and a good linear relation exists between them. The statistical errors of the ratio parameters in these effective interactions are analyzed. These new effective interactions are used to study the single-Lambda excited states, the equation of state of hypernuclear matter, and neutron-star properties with hyperons.

Automated summary

New effective Lambda N interactions for hypernuclei are proposed and the coupling constants ratios R-sigma and R-omega are determined by fitting experimental values. A good linear relation is found between the two ratios, and the statistical errors of the ratio parameters in these effective interactions are analyzed. These interactions are used to study single-Lambda excited states, hypernuclear matter equation of state, and neutron-star properties with hyperons.