Effects of $\Lambda$ hyperons on the nuclear equation of state in a Dirac-Brueckner-Hartree-Fock model

TL;DR

This paper investigates how the inclusion of $\Lambda$ hyperons affects the nuclear equation of state using a Dirac-Brueckner-Hartree-Fock model, considering different interaction potentials and many-body frameworks.

Contribution

It introduces a detailed analysis of $\Lambda$ hyperons' impact on nuclear matter within a Dirac-Brueckner-Hartree-Fock framework, incorporating various meson-exchange potentials.

Findings

Energy per baryon varies with $\Lambda$ hyperon fraction.

Results depend on the choice of nucleon-hyperon interaction model.

Dirac effects significantly influence the equation of state.

Abstract

We predict the energy per baryon in nuclear matter with non-zero fraction of $\Lambda$ hyperons. We include Dirac effects on the nucleons as well as the $\Lambda$ and describe how the latter is implemented. We use the nucleon-hyperon meson-exchange potentials from the Juelich group, the latest as well as an earlier version. The dependence of the results on the many-body framework and on the nucleon-hyperon interaction model is discussed.