2015/12/01 by Yeunhwan Lim, Chang Ho Hyun, K. Kwak +3
Physics and Astronomy · Earth and Planetary Sciences · #Pulsars and Gravitational Waves Research #Gamma-ray bursts and supernovae #High-pressure geophysics and materials
paper · doi:10.1142/s0218301315501001
We consider the so-called hyperon puzzle of neutron star (NS). We employ Skyrme force models for the description of in-medium nucleon–nucleon (NN), nucleon–Lambda hyperon ([Formula: see text]) and Lambda–Lambda ([Formula: see text]) interactions. A phenomenological finite-range force (FRF) for the [Formula: see text] interaction is considered as well. Equation of state (EoS) of NS matter is obtained in the framework of density functional theory, and Tolman–Oppenheimer–Volkoff (TOV) equations are solved to obtain the mass-radius relations of NSs. It has been generally known that the existence of hyperons in the NS matter is not well supported by the recent discovery of large-mass NSs ([Formula: see text]) since hyperons make the EoS softer than the one without them. For the selected interaction models, [Formula: see text] interactions reduce the maximum mass of NS by about 30%, while [Formula: see text] interactions can give about 10% enhancement. Consequently, we find that some Skyrme force models predict the maximum mass of NS consistent with the observation of [Formula: see text] NSs, and at the same time satisfy observationally constrained mass-radius relations.