Related papers: Hyperons and massive neutron stars: vector repulsi…
Using the well known quantum hadrodynamics (QHD), we study the effects of meson-hyperon coupling constants on the onset of hyperons in dense nuclear matter. We use the SU(3) symmetry group to fix all these coupling constants, constrained to…
The recent discoveries of massive neutron stars, such as PSR J$0348+0432$ and PSR J$1614-2230$, have raised questions about the existence of exotic matter such as hyperons in the neutron star core. The validity of many established equations…
Within a density-dependent relativistic mean-field model using in-medium meson-hadron coupling constants and meson masses, we explore effects of in-medium hyperon interactions on properties of neutron stars. It is found that the hyperonic…
Since 2013 the mass of pulsar PSR J0348+0432 ($M = 2.01\,M_{\odot}$) has provided a tight constraint on neutron star equation of state. However, a number of different analyses of the recently detected BNS merger (GW170817) point to a…
The measurement of the mass 1.97 +/- 0.04 M_sun for PSR J1614-2230 provides a new constraint on the equation of state and composition of matter at high densities. In this contribution we investigate the possibility that the dense cores of…
(Abridged) The recent measurement of the mass of two $2\, M_\odot$ pulsars has raised the question whether such large masses allow for the existence of exotic degrees of freedom, such as hyperons, inside neutron stars. In the present work…
We examine the roles the presence of hyperons in the cores of neutron stars may play in determining global properties of these stars. The study is based on estimates that hyperons appear in neutron star matter at about twice the nuclear…
The possibility of existence of hyperons in the recently measured $2M_\odot$ pulsar PSRJ1614-2230 is explored using a diverse set of nuclear equations of state calculated within the relativistic mean-field models. Our results indicate that…
Using various kinds of relativistic mean-field models as well as the quark-meson coupling model, we study in detail the properties of neutron stars. We find that the equation of state in SU(3) flavor symmetry can support a neutron star with…
We examine the role of hyperons in a neutron star based on the relativistic mean field approach. For nuclear matter below 1.5 times the normal nuclear density we constrain the model parameters by using the symmetric nuclear matter…
In the light of the recent discovery of a neutron star with a mass accurately determined to be almost two solar masses, it has been suggested that hyperons cannot play a role in the equation of state of dense matter in $\beta$-equilibrium.…
Since the discovery of neutron stars with masses around 2 solar masses the composition of matter in the central part of these massive stars has been intensively discussed. Within this paper we will (re)investigate the question of the…
The constituents of cold dense matter are still far from being understood. However, neutron star observations such as the recently observed pulsar PSR J1614-2230 with a mass of 1.97+/-0.04 M_solar help to considerably constrain the hadronic…
In this work I briefly review some of the effects of hyperons on the properties of neutron and proto-neutron stars. In particular, I revise the problem of the strong softening of the EoS, and the consequent reduction of the maximum mass,…
We consider the effect of hard core repulsion in the baryon-baryon interaction at short distance to the properties of a neutron star. We obtain that, even with hyperons in the interior of a neutron star, the neutron star mass can be as…
Using several relativistic mean field models (such as GM1, GM3, NL3, TM1, FSUGold and IU-FSU) as well as the quark-meson coupling model, we calculate the particle fractions, the equation of state, the maximum mass and radius of a neutron…
In this work, masses and radii of neutron stars are considered to investigate the effect of nuclear symmetry energy to the astrophysical observables. A relativistic mean field model with density-dependent meson-baryon coupling constants is…
Newly-determined mass of 1.97 $\pm$ 0.04 $M_{\odot}$ for PSR J1614-2230 has been a challenge for the neutron star with a hyperon core (namely hyperon star), since hyperons usually reduce the theoretical maximum mass of the star. In this…
We discuss the impact of strange hadrons, in particular hyperons, on the gross features of compact stars and on core-collapse supernovae. Hyperons are likely to be the first exotic species which appears around twice normal nuclear matter…
We study the properties of neutron star using the chiral quark-meson coupling model, in which the quark-quark hyperfine interaction due to the exchanges of gluon and pion based on chiral symmetry is considered. We also examine the effects…