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arXiv · 1402.0979

Isovector potential of $\Sigma$ in nuclei and neutron star matter

K. Tsubakihara·A. Ohnishi·T. Harada
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Abstract

We determine the coupling constants of $\Sigma$ hyperon with mesons in relativistic mean field (RMF) models using $\Sigma^-$ atomic shift data and examine the effects of $\Sigma$ on the neutron star maximum mass. We find that we need to reduce the vector-isovector meson coupling with $\Sigma$ ($g_{\rho\Sigma}$) from the value constrained by the SU(3)v symmetry in order to explain the $\Sigma^-$ atomic shifts for light symmetric and heavy asymmetric nuclei simultaneously. With the atomic shift fit value of $g_{\rho\Sigma}$, $\Sigma^-$ can emerge in neutron star matter overcoming the repulsive isoscalar potential for $\Sigma$ hyperons. Admixture of $\Sigma^-$ in neutron stars is found to reduce the neutron star maximum mass slightly.

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K. Tsubakihara, A. Ohnishi, T. Harada. 2014-02-05. Isovector potential of $\Sigma$ in nuclei and neutron star matter. https://arxiv.org/abs/1402.0979

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