arXiv subjects

E. K. Heide

Publications and source records attributed to E. K. Heide.

2 recordsLinked to original sources

arXiv1993

An Effective Lagrangian with Broken Scale and Chiral Symmetry Applied to Nuclear Matter and Finite Nuclei

We study nuclear matter and finite nuclei with a chiral Lagrangian which generalizes the linear $σ$ model and also accounts for the QCD trace anomaly by means of terms which involve the $σ$ and $\vmgπ$ fields as well as the glueball field $ϕ$. The form of the scale invariant term leading to an omega meson mass, after symmetry breaking, could involve coupling to $ϕ^2$ or $σ^2$ or some linear combination thereof. In fact an $ω_μω^μϕ^2$ form is strongly favored by the bulk properties of nuclei, which also rather strongly constrain the other parameters. A reasonable description of the closed shell nuclei oxygen, calcium and lead can be achieved, although the spin-orbit splittings are somewhat smaller than the experimental values.

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arXiv1993

Neutron Stars and Nuclei in the Modified Relativistic Hartree Approximation

We have examined the properties of neutron-rich matter and finite nuclei in the modified relativistic Hartree approximation for several values of the renormalization scale, $μ$, around the standard choice of $μ$ equal to the nucleon mass $M$. Observed neutron star masses do not effectively constrain the value of $μ$. However for finite nuclei the value $μ/M=0.79$, suggested by nuclear matter data, provides a good account of the bulk properties with a sigma mass of about 600 MeV. This value of $μ/M$ renders the effective three and four body scalar self-couplings to be zero at 60\% of equilibrium nuclear matter density, rather than in the vacuum. We have also found that the matter part of the exchange diagram has little impact on the bulk properties of neutron stars.

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