Hyperon puzzle and the RMF model with scaled hadron masses and coupling constants

15th International Conference on Strangeness in Quark Matter

Kolomeitsev, E.E.^1 ; Maslov, K.A.^2 ; Voskresensky, D.N.^2

Matej Bel University, Banska Bystrica

SK-97401, Slovakia^1

National Research Nuclear University (MEPhI), Moscow

115409, Russia^2

关键词: Baryonic matter;    Coupling constants;    Equation of motion;    Equation of state;    Neutron stars;    Relativistic mean fields;    Saturation density;    Scalar fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/668/1/012064/pdf
DOI  :  10.1088/1742-6596/668/1/012064

来源: IOP

【 摘 要 】

The equation of state of cold baryonic matter is studied within a relativistic mean-field model with hadron masses and coupling constants depending on a scalar field. We demonstrate that if the effective nucleon mass stops to decrease with a density increase at densities n > n∗> n0, where n0is the nuclear saturation density, the equation of state stiffens for these densities and the limiting neutron star mass increases. The stabilization of the nucleon mass can be realised if in the equation of motion for the scalar mean-field there appear a term sharply varying in a narrow vicinity of the field value corresponding to the density n∗. We show several possible realizations of this mechanism getting sufficiently stiff equations of state. The appearance of hyperons in dense neutron star interiors is accounted for. The obtained equations of state remain sufficiently stiff if the reduction of the φ meson mass is incorporated. Thereby, the hyperon puzzle can be resolved.