$\delta$ meson effects on neutron stars in the modified quark-meson coupling model

Abstract

The properties of neutron stars are investigated by including $\delta$ meson field in the Lagrangian density of modified quark-meson coupling model. The ${\Sigma }^{-}$ population with $\delta$ meson is larger than that without $\delta$ meson at the beginning, but it becomes smaller than that without $\delta$ meson as the appearance of ${\Xi }^{-}$. The $\delta$ meson has opposite effects on hadronic matter with or without hyperons: it softens the EOSes of hadronic matter with hyperons, while it stiffens the EOSes of pure nucleonic matter. Furthermore, the leptons and the hyperons have the similar influence on $\delta$ meson effects. The $\delta$ meson increases the maximum masses of neutron stars. The influence of $({\sigma }^{\ast },\varphi )$ on the $\delta$ meson effects are also investigated.

Comments: 10 pages, 6 figures, 4 tables