Effective field theory for neutron stars with strong $\Sigma^-$-hyperon repulsion

We investigate the role of many-body correlations in the maximum mass of neutron stars using the effective relativistic QHD-model with parameterized couplings which represents an extended compilation of other effective models found in the literature. Our model exhausts the whole fundamental baryon octet (n, p, Σ–, Σ0, Σ+, Λ, Ξ–, Ξ0) and simulates corrections to the minimal Yukawa couplings by considering many-body nonlinear self-couplings and meson-meson interaction terms involving scalar-isoscalar (σ, σ*), vector-isoscalar (ω, ϕ), vector-isovector (ρ) and scalar-isovector (δ). Following recent experimental results, we consider in our calculations the extreme case where the Σ– experiences such a strong repulsion that it does not appear at all in nuclear matter. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)