Related papers: $\Delta$ isobars in hyperon stars in a modified qu…
We show that the contact couplings of neutral pseudoscalar and axial mesons to the nucleon are proportional to $\Delta s$, the fraction of nucleon spin carried by the strange quark sea, and thus are strongly suppressed relative to the…
The hadron-quark phase transition in the interior of compact stars is investigated, when the transition proceeds through a mixed phase. The hadronic phase is described in the framework of relativistic mean-field theory, when also the…
Astronomical observations reveal a gap in the mass spectrum of relativistic objects: neither black holes nor neutron stars with 2 - 5 solar masses have ever been observed. In this article I proceed in presenting the scenario which discloses…
We explore the impact of in-medium modification of the properties of vector mesons on the nuclear equation of state and neutron star properties. It is found that in-medium modifications stiffen the nuclear equation of state considerably. If…
We examine the properties of composite octet baryons in the nuclear medium and neutron star matter. The internal quark-diquark structure of the octet baryons and the equations of state of nuclear matter and neutron star matter in the mean…
The possible existence of an H-dibaryon near the $\Lambda-\Lambda$ threshold has still not been decided experimentally. This raises the question of the potential effects on neutron stars if it does exist. We explore the consequences within…
The possible conditions for hadron-quark phase transition in hybrid star cores are investigated in the present work. For the hadronic matter part the effective chiral model is adopted. Exotic baryonic degrees like hyperons and the delta…
It is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high-pressure environment in which several intriguing particles processes may compete with each other. These range from the generation…
We investigate the properties of the hadron-quark mixed phase, often termed the \textit{pasta} phase, expected to exist in the cores of massive neutron stars. To construct the equations of state (EoS), we combine an analytical…
The properties of the kaon, $K$, and antikaon, $\kbar$, in nuclear medium are studied in the quark-meson coupling (QMC) model. Employing a constituent quark-antiquark (MIT bag model) picture, their excitation energies in a nuclear medium at…
A recently introduced relativistic nuclear energy density functional, constrained by features of low-energy QCD, is extended to describe the structure of hypernuclei. The density-dependent mean field and the spin-orbit potential of a…
The properties of compact stars and their formation processes depend on many physical ingredients. The composition and the thermodynamics of the involved matter is one of them. We will investigate here uniform strongly interacting matter at…
Recent developments in neutron star theory and observation are discussed. Based on modern nucleon-nucleon potentials more reliable equations of state for dense nuclear matter have been constructed. Furthermore, phase transitions such as…
Recent measurements of neutron star mass from several candidates (PSR J$1614-2230$, PSR J$0348+0432$, MSP J$0740+6620$) set the lower bound on the maximum possible mass for this class of compact objects $\sim 2$ M$_\odot$. Existence of…
Recent equations of state for dense nuclear matter are discussed with possible phase transitions arising in neutron stars such as pion, kaon and hyperon kondensation, superfluidity and quark matter. Specifically, we treat the nuclear to…
The spectra of the nucleons, $\Delta$ resonances and the strange hyperons are well described by the constituent quark model if in addition to the harmonic confinement potential the quarks are assumed to interact by exchange of the $SU(3)_F$…
The recent measurement of a $1.97\pm 0.04$ solar-mass pulsar places a stringent lower bound on the maximum mass of compact stars and therefore challenges the existence of any agents that soften the equation of state of ultra-dense matter.…
A structured mixed phase consisting of quark and hadron phases is numerically studied with the Coulomb screening effect and the surface effect. We carefully introduced the Coulomb potential, so that a geometrical structure becomes…
We try to single out some qualitative new effects of the coupling to the $\delta$-isovector-scalar meson introduced in a minimal way in a phenomenological hadronic field theory. Results for the equation of state ($EOS$) and the phase…
Baryon and quark superfluidity in the cooling of neutron stars are investigated. Observations could constrain combinations of the neutron or Lambda-hyperon pairing gaps and the star's mass. However, in a hybrid star with a mixed phase of…